State Health Data Portals¶
Catalog of official state health data portals, one entry per state. Every source this repo collects today is federal; this doc is for finding state-level data that CDC either doesn't publish nationally or publishes only in aggregate.
For the subset that has been probed against a live endpoint, with dataset IDs and column names confirmed, see State & Local Sources. That page goes deep on a dozen portals; this one goes wide across all 51 jurisdictions.
Every URL here was found through a live search and points at a state agency or its data platform. Where a state runs more than one system, the primary query/download portal is listed first.
Common Platforms¶
Several states run the same underlying software, which is worth knowing before writing a scraper. If you can parse one, you can usually parse its siblings.
- IBIS-PH (Indicator-Based Information System for Public Health): open-source query system originally built by the Utah Department of Health. Adopting states rename it (NJSHAD in New Jersey, NM-IBIS in New Mexico). Layout is consistent: indicator reports, community profiles, and dataset queries that emit custom tables, charts, and maps.
- Socrata (now Tyler Data & Insights): powers many statewide open data portals. Every
dataset gets a SODA API endpoint, so
https://<host>/resource/<id>.csvworks the same waydata.cdc.govdoes in this project. See CDC Open Data for the query syntax, andsrc/cdc_open/for a client that already speaks it. - ArcGIS Hub: used for map-first and dashboard-first publishing. Underlying data is usually reachable as GeoJSON or CSV through the feature service, though it is rarely advertised.
- Environmental Public Health Tracking (EPHT): CDC-funded state tracking networks with a shared data model, covering environmental hazards next to health outcomes.
Major Systems by State¶
Grouping the 51 jurisdictions by the software behind the portal. Anything you build for one member of a family should mostly transfer to its siblings.
| System | States | What it means for ingestion |
|---|---|---|
| Socrata / Tyler Data & Insights | NY (health.data.ny.gov, data.ny.gov), CT, MD, CO, OR, NJ, VA, UT | Every dataset has a SODA endpoint. https://<host>/resource/<id>.csv plus $select, $where, $group works exactly like data.cdc.gov. Server-side aggregation means you can sum a facility-level table without downloading it. |
| CKAN | CA (data.chhs.ca.gov), IN (hub.mph.in.gov) | JSON catalog API at /api/3/action/package_search and package_show. Resources are plain CSV downloads, so discovery is scriptable but filtering is not. |
| ArcGIS Hub | DC, RI, IN, KS, plus CDPH's geospatial site in CA | Map-first. Underlying data is usually reachable as GeoJSON or CSV through the feature service, though rarely advertised. |
| IBIS-PH | UT (origin), NM, HI, NJ (as NJSHAD) | Shared URL structure and page layout: indicator reports, community profiles, dataset queries. Worth writing one scraper for the family rather than four. |
| CDC Environmental Public Health Tracking | ME, MA, MN, IA, KS, KY, LA, MO, NM, OR, WA | Shared data model and Nationally Consistent Data Measures, so counties compare across states. Environmental hazards sit next to health outcomes. |
| Network of Care | NV | Third-party platform rather than state-built software. |
| Custom state-built query systems | PA (EDDIE), GA (OASIS), WI (WISH), MO (MICA), OK (OK2SHARE), NC, SC (SCAN), FL (CHARTS), IL (IQuery), CO (CoHID), NH (WISDOM), MS (MSTAHRS), AL, AZ, MI, OH | One-off form-post interfaces. Good data, no API, and each needs its own scraper. |
Northeast¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Connecticut | CT DPH Data & Research | https://portal.ct.gov/dph/resources-and-records/data-research | Vital records, CT Tumor Registry, BRFSS, hospital discharge and quality data. Statewide Socrata portal at data.ct.gov carries the machine-readable copies. |
| Maine | Maine CDC Data & Reports | https://www.maine.gov/dhhs/mecdc/data-reports | Vital statistics via the Data, Research and Vital Statistics office, plus BRFSS and PRAMS. |
| Maine | Maine Tracking Network | https://data.mainepublichealth.gov/tracking/ | EPHT system: air quality, birth defects, cancer, lead poisoning, Lyme disease. Hospitalization inputs come from the Maine Health Data Organization (MHDO). |
| Massachusetts | DPH Data Library | https://www.mass.gov/dph-data-library | Catalog of dashboards, reports, and downloadable datasets. Absorbed the Population Health Information Tool (PHIT). |
| Massachusetts | Massachusetts Health Data Tool | https://healthdatatool.mass.gov/ | State and community reports on health outcomes and social determinants. |
| Massachusetts | MA Environmental Public Health Tracking | https://matracking.ehs.state.ma.us/ | Environment and health by state, county, community, and region. |
| New Hampshire | NH DHHS Data Portal (formerly NH Health WISDOM) | https://wisdom.dhhs.nh.gov/wisdom/ | Aggregates 40+ datasets into hundreds of indicators at town, county, and state level. Most datasets update annually. |
| New Jersey | NJSHAD (NJ State Health Assessment Data) | https://www-doh.nj.gov/doh-shad | IBIS-PH system, 200+ public health indicators, with dataset queries producing custom tables and maps. Statewide Socrata portal at data.nj.gov. |
| New York | Health Data NY | https://health.data.ny.gov/ | The strongest state health portal in the country: 500+ datasets on Socrata, full SODA API, extensive metadata. Covers Medicaid, COVID-19, facility inspections, WIC, and hospital quality. |
| New York | NYSDOH Data & Reports | https://www.health.ny.gov/statistics/ | Narrative statistics and reports that sit alongside the open data. |
| Pennsylvania | EDDIE | https://www.phaim.health.pa.gov/EDD/ | Enterprise Data Dissemination Informatics Exchange. Custom tables, charts, maps, and county profiles from vital and health statistics, 1990 to present, down to municipality, by race and age group. |
| Rhode Island | RIDOH Data | https://health.ri.gov/data | Hospital discharge, maternal and child health, opioid and stimulant data hubs, HealthFacts RI all-payer claims database. |
| Rhode Island | RIDOH Map Portal | https://rihealth.maps.arcgis.com/ | ArcGIS Hub for geographic health data. |
| Vermont | Health Statistics & Vital Records | https://www.healthvermont.gov/stats | A-Z data library covering cancer, immunizations, birth defects, behavioral trends, and vital records. |
| Vermont | Vermont Health Data Dashboard | https://healthdata.vermont.gov/ | Dashboard front end for the same statistics. |
South Atlantic¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Delaware | My Healthy Community | https://myhealthycommunity.dhss.delaware.gov/ | Launched 2019 by the Division of Public Health. Neighborhood-level population health, environmental, and social determinant data down to zip code and census tract. Indicators include maternal and child health, infectious disease, lead poisoning, suicide, and homicide. DPH has said data is moving to the Delaware Open Data Portal. |
| District of Columbia | DC Health Data and Statistics | https://dchealth.dc.gov/service/data-and-statistics | Surveillance dashboards by ward. |
| District of Columbia | Open Data DC | https://opendata.dc.gov/ | ArcGIS Hub with API access, health datasets included. |
| Florida | FLHealthCHARTS | https://www.flhealthcharts.gov/ | Community Health Assessment Resource Tool Set, run by the Bureaus of Community Health Assessment and Vital Statistics. Vital statistics, chronic disease (diabetes, asthma, cancer, COPD, heart disease, stroke), and health resource counts. One of the better query tools in the country. |
| Georgia | OASIS | https://oasis.state.ga.us/ | Online Analytical Statistical Information System, built by the Office of Health Indicators for Planning. Vital statistics, hospital discharge, ER visits, arboviral surveillance, YRBS, BRFSS, STD, motor vehicle crash, and population. Census-tract maps via the OASIS mapping tool. |
| Maryland | Maryland Vital Statistics Administration | https://health.maryland.gov/vsa/ | Births, deaths, marriages, and annual published reports. |
| Maryland | Maryland Open Data | https://opendata.maryland.gov/ | Socrata, 1,000+ datasets statewide, with a Health and Human Services category carrying MDH data. |
| North Carolina | NC State Center for Health Statistics | https://schs.dph.ncdhhs.gov/ | The state's central health statistics shop. |
| North Carolina | NC Health Data Query System | https://schs.dph.ncdhhs.gov/interactive/query/ | Custom reports on births, birth defects, mortality, population, and pregnancies by age, race, and county. Companion NC Health Atlas maps the same at county level. |
| South Carolina | SCAN (SC Community Assessment Network) | https://apps.dhec.sc.gov/Health/scan/scan/index.aspx | Tables, charts, and maps at region, county, or zip level. Births, deaths, PRAMS, fetal death, infant and child health, childhood lead, and cancer registry data. |
| South Carolina | SC DPH Public Health Data | https://dph.sc.gov/professionals/public-health-data | Dashboard index, including the SC County Health Profile. |
| Virginia | VDH Data Portal | https://www.vdh.virginia.gov/data/ | Interactive maps and visualizations for cancer, communicable disease, demographics, health behavior, and opioid addiction. Includes the Health Opportunity Index. |
| Virginia | VDH Division of Health Statistics | https://apps.vdh.virginia.gov/HealthStats/ | Vital statistics query and published reports. Statewide open data at data.virginia.gov. |
| West Virginia | WV Health Statistics Center | https://dhhr.wv.gov/HSC | Official vital records repository plus the statewide BRFSS survey. Statistical Services publishes the derived tables. |
South Central¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Alabama | ADPH Data | https://www.alabamapublichealth.gov/data/ | Department-wide data index. |
| Alabama | ADPH Statistical Query System | https://www.alabamapublichealth.gov/healthstats/statistical-query.html | Separate natality and mortality query systems producing frequency tables for Alabama resident births and deaths. |
| Arkansas | ADH Data, Statistics & Registries | https://healthy.arkansas.gov/programs-services/data-statistics-registries/ | Vital statistics, county health fact sheets, hospital discharge data system, and health workforce statistics. Mostly reports rather than a query tool. |
| Kentucky | Kentucky HEALTHTRACKING Data Portal | https://healthtracking.ky.gov/data-portal/Pages/default.aspx | EPHT-based portal from the Department for Public Health. Most data is county level. |
| Louisiana | LDH Health Data Explorer | https://healthdata.ldh.la.gov/ | CDC-funded tracking portal launched 2016, covering environmental hazards alongside diabetes, asthma, and birth defects. |
| Louisiana | LAHIDD | https://ldh.la.gov/page/lahidd | Hospital Inpatient Discharge Database, 1998 onward. Aggregate and de-identified extracts available on request, not for commercial use. |
| Mississippi | MSDH Data and Statistics | https://msdh.ms.gov/page/31.html | Vital statistics reports back to 1995. The MSTAHRS web query system covers vital statistics, and is the route to 2020 and later data. |
| Oklahoma | OK2SHARE | https://www.health.state.ok.us/ok2share/ | Oklahoma Statistics on Health Available for Everyone. Births from 1975, deaths from 1980, inpatient discharge from 2002, outpatient from 2006, plus BRFSS, YRBS, and birth defect, cancer, STI/HIV, and injury registries. No data request needed. |
| Oklahoma | State of the State's Health | https://stateofstateshealth.ok.gov/ | Indicator dashboard layer over the same data. |
| Tennessee | TDH Health Data | https://healthdata.tn.gov/ | Locate and visualize health, environmental, and community data, with downloads for the visualizations and underlying data. |
| Tennessee | TN Health Statistics | https://www.tn.gov/health/health-program-areas/statistics.html | Reports, fact sheets, and an interactive reportable disease dashboard at state and county/region level. |
| Texas | Texas Health Data | https://healthdata.dshs.texas.gov/ | Interactive dashboards from the DSHS Center for Health Statistics: vital events, BRFSS, YRBS, hospital discharge inpatient and outpatient, nursing workforce, infant and maternal health. |
Great Lakes¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Illinois | IQuery | https://iquery.illinois.gov/iquery/ | Vital statistics, STDs, childhood lead exposure, mortality, trauma registry, traffic crashes, and hospital discharge. Note the catch: the IQuery dashboard requires an Illinois.gov account, requested through DPH.IQuery@Illinois.gov, so it is not openly scrapable. |
| Illinois | IDPH Data & Statistics | https://dph.illinois.gov/data-statistics.html | Public reports and the IQuery landing pages. |
| Indiana | Public Health Data Navigator | https://www.in.gov/health/directory/office-of-the-commissioner/public-health-data-navigator/ | Index of dashboards for chronic disease, maternal and child health, injury, infectious disease, lead, tobacco, environmental health, vital records, and immunizations. |
| Indiana | Indiana Data Hub | https://hub.mph.in.gov/ | Statewide CKAN-style hub run by the Management Performance Hub, with an Indiana Department of Health organization page. Best machine-readable route for Indiana. |
| Michigan | Michigan Public Health Data Dashboards | https://www.michigan.gov/mdhhs/inside-mdhhs/statisticsreports/michigan-public-health-data-dashboards | Community profiles down to legislative district. |
| Michigan | Michigan Health Statistics (Vital Records & Health Statistics) | https://www.mdch.state.mi.us/osr/index.asp | Long-running query site for natality, mortality, hospitalization, and cancer incidence by county and local health department. |
| Ohio | Ohio Public Health Data Warehouse | https://odh.ohio.gov/explore-data-and-stats/interactive-applications/ohio-public-health-data-warehouse | Self-service query tool for the most recent Ohio public health data. Some functions sit behind an OHID login. |
| Ohio | ODH Explore Data & Stats | https://odh.ohio.gov/explore-data-and-stats/data-and-stats-welcome/ | Entry point for the warehouse and the other interactive applications. |
| Wisconsin | WISH (Wisconsin Interactive Statistics on Health) | https://www.dhs.wisconsin.gov/wish/index.htm | Among the most complete state query systems. Modules for births, deaths, cancer incidence and mortality, injuries, opioids, violent deaths, behavioral risks, and population, at state, region, county, city, zip, and local health department level. |
Plains¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Iowa | Iowa Public Health Tracking Portal | https://tracking.idph.iowa.gov/Reports | Health effects (asthma, birth defects), environmental hazards, and exposure data. Much of it is published as Nationally Consistent Data Measures, so counties compare cleanly against other EPHT states. Counts of five or fewer are suppressed and shown as an asterisk. |
| Iowa | Iowa HHS Data & Reports | https://hhs.iowa.gov/about/data-reports | Health statistics index around the tracking portal. |
| Kansas | Kansas Information for Communities (KIC) | https://kic.kdheks.gov/ | Query system for public health datasets and county statistics. |
| Kansas | KDHE Data Dashboards | https://www.kdhe.ks.gov/2046/Data-Dashboards | A to Z index across chronic conditions, disease and immunization, environmental health, injury prevention, maternal and child health, and social determinants. |
| Minnesota | MN Public Health Data Access | https://data.web.health.state.mn.us/home | Run by the Minnesota Tracking Program, one of 26 CDC EPHT grantees. More than 20 health and environment topics as charts, tables, and maps, with downloads. |
| Missouri | MOPHIMS | https://healthapps.dhss.mo.gov/MoPhims/MOPHIMSHome | Missouri Public Health Information Management System, launched 2017 over a lineage going back to the 1990s. Two halves: Community Data Profiles, and the MICA query tool below. |
| Missouri | MICA (Missouri Information for Community Assessment) | https://healthapps.dhss.mo.gov/MoPhims/MICAHome | Custom tables by year, age, gender, race, and county or zip, with age-adjusted rates, charts, and maps, all downloadable. Note the unusually granular cell-suppression rules, which change what small-area queries will return. |
| Nebraska | Nebraska DHHS Public Data | https://dhhs.ne.gov/Pages/Public-Data.aspx | Department data platform, with a companion Nebraska Public Health Atlas. |
| North Dakota | ND HHS Health Data and Statistics | https://www.hhs.nd.gov/health/data-statistics | Indicator dashboard, county health profiles, BRFSS, cancer registry, and vital statistics. |
| South Dakota | SD DOH Vital Statistics | https://doh.sd.gov/health-data-reports/vital-statistics/ | Mostly published PDF reports (natality, infant and fetal mortality, mortality, marriage and divorce, infectious disease) rather than a query tool. Leading health indicator comparisons are published alongside. |
Mountain West¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Arizona | AZDHS Data Portal | https://data.azdhs.gov/ | Consolidates department data into one place: data explorers, dashboards, searchable report and database catalogs, GIS assets, and a data request form. |
| Arizona | Population Health and Vital Statistics | https://pub.azdhs.gov/health-stats/ | Bureau of Public Health Statistics tables and trend reports. |
| Colorado | CoHID (Colorado Health Information Dataset) | https://cdphe.colorado.gov/cohid | Query system for births, deaths, population estimates, behavioral risk factors, birth defects, cancer incidence, pregnancy risk assessment, and injury hospitalizations. The one to use for raw numbers. |
| Colorado | CDPHE Explore Data | https://cdphe.colorado.gov/explore-data | Entry point for CoHID and for VISION, a chronic disease and behavioral health visualization tool. Statewide Socrata portal at data.colorado.gov. |
| Idaho | Idaho Population Health Data | https://www.gethealthy.dhw.idaho.gov/ | Population health measures including vital statistics sections on births and population. |
| Idaho | DHW Reports and Statistics | https://healthandwelfare.idaho.gov/about-dhw/reports-and-statistics | Bureau of Vital Records and Health Statistics fact sheets on births and pregnancy, chronic disease, drug deaths, mortality, substance abuse, and suicide. Largely PDF. |
| Montana | MT DPHHS Health Data and Statistical Reports | https://dphhs.mt.gov/statisticalinformation/ | Report-driven rather than interactive. |
| Montana | Vital Statistics Analysis Unit | https://dphhs.mt.gov/publichealth/Epidemiology/oess-vs | Vital records back to 1907. BRFSS, hospital discharge, syndromic surveillance, tumor registry, and immunization registry are available through a formal data request rather than self-service. |
| Nevada | Nevada Health Statistics Portal (Network of Care) | http://state.nv.networkofcare.org/ph/ | Key indicators with customizable queries and county-level geo-mapping, run on the Network of Care platform rather than state-built software. |
| Nevada | DPBH Office of Public Health Informatics and Epidemiology | https://www.dpbh.nv.gov/programs/ophie/public-health-informatics-and-epidemiology-ophie-community/ | Program-level data and publications. |
| New Mexico | NM-IBIS | https://ibis.doh.nm.gov/ | IBIS-PH system with indicator reports (teen births, smoking, drug overdose deaths) and per-county community profiles, partnered with the state EPHT network. |
| New Mexico | NMDOH Health Data | https://www.nmhealth.org/data/ | Department data index. |
| Utah | Utah IBIS-PH | https://ibis.health.utah.gov/ibisph-view/ | The original IBIS-PH, still among the deepest. Indicator reports, custom query modules with charts and maps, community snapshots for local health districts and Utah Small Areas, and 7,000+ publications in the Utah Public Health Library. |
| Wyoming | WDH Vital Statistics Services | https://health.wyo.gov/admin/vitalstatistics/ | Official custodian of vital records. Note that the public-facing VSS portal at wyomingvitalrecords.wyo.gov is for ordering certificates, not for statistics. Wyoming publishes the least self-service health data of any state surveyed here. |
Pacific¶
| State | Portal | URL | Notes |
|---|---|---|---|
| Alaska | Alaska Health Data (HAVRS) | https://health.alaska.gov/en/education/alaska-health-data/ | Health Analytics and Vital Records Section. Annual reports for vital statistics, health facilities data reporting, and cancer. Anything beyond the published reports goes through the HAVRS data request application. |
| California | CalHHS Open Data Portal | https://data.chhs.ca.gov/ | CKAN-based, with CDPH publishing roughly 109 datasets: healthcare-associated infections, COVID-19 vaccination, WIC vendors, hospital discharges and ER encounters, licensed facilities. Best-in-class for machine-readable access alongside New York. |
| California | CDPH Geospatial Resources | https://data-cdphdata.opendata.arcgis.com/ | ArcGIS Hub for the spatial layers. Statewide portal at data.ca.gov. |
| Hawaii | Hawai'i Health Data Warehouse | https://hhdw.org/ | Partnership between the state Department of Health and the University of Hawai'i Office of Public Health Studies. |
| Hawaii | Hawaii-IBIS | http://ibis.hhdw.org/ibisph-view/ | IBIS-PH query system over the warehouse, sliceable by demographic and socioeconomic dimensions. Served over plain HTTP at time of writing. |
| Oregon | OHA Data and Statistics | https://www.oregon.gov/oha/PH/DATASTATISTICS/Pages/index.aspx | Public Health Division index for health behaviors, disease, and injury data. |
| Oregon | Vital Statistics Data Maps | https://www.oregon.gov/oha/PH/BIRTHDEATHCERTIFICATES/VITALSTATISTICS/Pages/data-maps.aspx | Birth and death records geocoded to residential address since 2002, so maps go below county to census tract and zip. Statewide Socrata portal at data.oregon.gov. |
| Washington | Washington Tracking Network Data Portal | https://doh.wa.gov/data-and-statistical-reports/washington-tracking-network-wtn/data-portal | Select by topic, time period, and geography (state, county, census tract), output as tables, charts, or maps, all downloadable. The most download-friendly EPHT portal reviewed. |
| Washington | WA DOH Health Statistics | https://doh.wa.gov/data-and-statistical-reports/health-statistics | Births, deaths, abortions, marriages, divorces, health factors, and hospitalizations. |
What This Means For Adding State Data¶
If the goal is collecting state data alongside the CDC series this repo already archives, the states sort into four tiers by how much work ingestion would take.
Genuinely automatable today, because they expose a documented API over stable dataset IDs:
New York (health.data.ny.gov, Socrata/SODA), California (data.chhs.ca.gov, CKAN), and
the statewide Socrata portals in Connecticut, Maryland, Colorado, Oregon, and New Jersey.
These behave like data.cdc.gov and would need almost no new fetching code.
Query systems with good data but no API: Wisconsin WISH, Georgia OASIS, Missouri MICA, Oklahoma OK2SHARE, Utah and New Mexico IBIS-PH, Florida CHARTS, Pennsylvania EDDIE, and North Carolina's query system. These generate tables on demand from form posts. Scraping is possible but brittle, and the IBIS-PH states are worth attacking together since they share a URL structure.
Report-only states, where the data exists but arrives as PDF: South Dakota, Idaho, Montana, Arkansas, Alaska, and West Virginia. Extracting trend series from these means parsing annual reports, and the effort rarely beats just using the CDC national files.
Blocked or restricted: Illinois IQuery requires an Illinois.gov account, parts of Ohio's warehouse sit behind an OHID login, and Montana routes most non-vital data through a formal request process. Wyoming publishes the least of any state here.
Two caveats that apply everywhere. Small-cell suppression differs by state, which changes what county and zip queries return: Iowa suppresses counts of five or fewer, and Missouri runs a multi-level suppression scheme that varies by user access. And state numbers will not tie out against the CDC series this repo collects, because the vintage, residency rules, and age-adjustment standards differ.
Validating NY and CA Against CDC¶
Measured August 2026 by pulling weekly respiratory admissions from each state portal and
comparing them against the same week in CDC NHSN (data.cdc.gov/resource/ua7e-t2fy),
which carries a per-jurisdiction breakdown plus a USA row. The result changes which of
the two states is worth adding.
California republishes CDC. Its Respiratory Virus Dashboard is not an independent count. For flu admissions, 89 of 90 comparable weeks are numerically identical, the sole exception being the week ending 2025-11-29 (CA 218, CDC 217). For COVID admissions, 88 of 98 weeks are identical. Collecting California as a separate series would duplicate data this repo already archives under a different name.
The COVID divergence is confined to nine weeks, from 2024-09-07 through 2024-10-26, where
California ran higher than CDC by between 25% and 213%. Exact agreement begins the week
ending 2024-11-02 and holds through the present. That boundary lines up with the end of
the voluntary-reporting era that health-charts' DATA_SOURCES.md flags for RSV, which suggests
California kept fuller counts while NHSN reporting was optional and then aligned once it
was not. Treat that as the likely explanation rather than a confirmed one.
New York is genuinely independent, and consistently higher. Summing the facility-level
table vgyq-b7tb to statewide weekly COVID admissions gives numbers above CDC's New York
figure in every one of the 43 overlapping weeks (2025-10-04 through 2026-07-25), with a
median ratio of 1.23 and a range of 1.09 to 2.29. Flu tells the same story: summing the
county-by-age table iye6-rifr across 66 weeks runs above CDC, by 5% to 17% during peak
weeks. The headline 34% mean absolute difference for flu is misleading, since off-season
weeks with tiny counts dominate the percentage; peak-season agreement is much tighter.
The direction is stable enough that New York looks like a broader denominator (state reporting mandates covering more facilities than NHSN captures) rather than noise, but neither portal documents the reconciliation, so the cause is unconfirmed.
Scale. Across the 2024-25 season New York accounted for 6.6% of national COVID admissions and California 9.5%; in 2025-26, 6.3% and 8.8%. California's share sits well below its population share, roughly 39.4 million of about 340 million, or 11.6%, per the Census Bureau's Vintage 2024 estimates.
Practical upshot: New York adds a real second view and California does not. Any state series should be labeled as state-sourced rather than blended into a national line, since the two sources disagree by a fifth or more on the same weeks.