# NOAA NCEI Climate Data Online and Access Data Service

NOAA's archive of historical weather and climate observations, including daily station records (GHCN-Daily) from over 90,000 land stations, with a key-less data service API, a token-based CDO API and bulk file downloads.

- Category: Weather and climate · by NOAA National Centers for Environmental Information (NCEI)
- Website: https://www.ncei.noaa.gov/cdo-web/
- Live data: yes
- Checked on the official pages: 2026-10-23

## API

- Official API: yes, docs https://www.ncei.noaa.gov/support/access-data-service-api-user-documentation
- Key needed: no
- Price: Free; limits: Access Data Service: no key needed (tested). Older CDO Web Services v2 (https://www.ncei.noaa.gov/cdo-web/api/v2/) needs a free token, limited to five requests per second and 10,000 requests per day
- Base URL: https://www.ncei.noaa.gov/access/services/data/v1
- Formats: csv, json, ssv, pdf, netcdf

Example request:

```
https://www.ncei.noaa.gov/access/services/data/v1?dataset=daily-summaries&stations=USW00094728&startDate=2024-01-01&endDate=2024-01-07&dataTypes=TMAX,TMIN,PRCP&format=json
```

## Data and license

- Download: https://www.ncei.noaa.gov/pub/data/ghcn/daily/ (csv, text)
- License: public domain (US); WMO Resolution 40 limits on some non-US station data (https://www.ncei.noaa.gov/sites/default/files/2023-12/NCEI%20PD-10-2-02%20-%20Open%20Data%20Policy%20Signed.pdf); covers NOAA-produced environmental data are US public domain; GHCN data for non-US locations exchanged under WMO Resolution 40 may not be re-exported for commercial services; datasets ask to be cited
- Commercial use with conditions
- Credit required
- Can be embedded
- Quote (api_official): "The NCEI Access Data Service queries use HTTP 1.1 GET request and the endpoint is located off the base URL at .../access/services/data/v1 ." (https://www.ncei.noaa.gov/support/access-data-service-api-user-documentation)
- Quote (api_key): "An access token is required to use the API, and each token will be limited to five requests per second and 10,000 requests per day." (https://www.ncdc.noaa.gov/cdo-web/webservices/v2)
- Quote (limits): "An access token is required to use the API, and each token will be limited to five requests per second and 10,000 requests per day." (https://www.ncdc.noaa.gov/cdo-web/webservices/v2)
- Quote (api_price): "Climate Data Online (CDO) provides free access to NCDC's archive of global historical weather and climate data in addition to station history information." (https://www.ncei.noaa.gov/cdo-web/)
- Quote (formats): "These are the available formats: csv — Comma-Separated Values (CSV) ssv — Space-Separated Values (SSV) json — JavaScript Object Notation (JSON) pdf — Portable Document Format (PDF) netcdf — Network Common Data Form (NetCDF)" (https://www.ncei.noaa.gov/support/access-data-service-api-user-documentation)
- Quote (license): "Environmental data and information produced by NOAA or any Federal agency are available fully and openly to data users unless explicitly exempt from release by Federal law, regulation or policy. These data are in the public domain in the United States." (https://www.ncei.noaa.gov/sites/default/files/2023-12/NCEI%20PD-10-2-02%20-%20Open%20Data%20Policy%20Signed.pdf)
- Quote (commercial): "For non-U.S. locations data, the data or any derived product shall not be provided to other users or be used for the re-export of commercial services." (https://www.ncei.noaa.gov/pub/data/cdo/documentation/GHCND_documentation.pdf)
- Quote (commercial_wmo): "This allows WMO member countries to place restrictions on the use or re-export of their data for commercial purposes outside of the receiving country." (https://www.ncei.noaa.gov/pub/data/cdo/documentation/GHCND_documentation.pdf)
- Quote (attribution): "Use Constraints Cite as: Menne, Matthew J., Imke Durre, Bryant Korzeniewski, Shelley McNeill, Kristy Thomas, Xungang Yin, Steven Anthony, Ron Ray, Russell S. Vose, Byron E.Gleason, and Tamara G. Houston (2012)" (https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ncdc:C00861/html)
- Quote (embed): "These data are in the public domain in the United States." (https://www.ncei.noaa.gov/sites/default/files/2023-12/NCEI%20PD-10-2-02%20-%20Open%20Data%20Policy%20Signed.pdf)
- Quote (download): "These data include quality controlled daily, monthly, seasonal, and yearly measurements of temperature, precipitation, wind, and degree days as well as radar data and 30-year Climate Normals." (https://www.ncei.noaa.gov/cdo-web/)

## Rules for an agent

- Prefer the key-less Access Data Service (/access/services/data/v1?dataset=daily-summaries&stations=...&format=json); use GHCN station IDs like USW00094728 (New York Central Park); the token-based cdo-web/api/v2 is only needed for its search endpoints.
- Cite NOAA NCEI and the dataset (e.g. GHCN-Daily, Menne et al. 2012) where the data is used.
- For commercial products, stick to US station data or check the WMO Resolution 40 note: non-US GHCN data may not be re-exported for commercial services.
- The cdo-web/api/v2 token is limited to 5 requests/second and 10,000/day; keep Access Data Service requests to reasonable date ranges.

Human page: https://agentgid.com/resources/noaa-ncei-climate-data-online/
Source: AgentGid (agentgid.com). Facts are quoted from the site's own pages; check the license page before you ship.