Hourly US weather history grid since 1979 (NOAA)
What it measures. A detailed grid of past weather across the U.S. and Alaska, recording hourly rainfall, temperature, humidity, air pressure, sunlight and other radiation, and wind for every spot roughly every 800 meters.
How it's made. NOAA stitched decades of observations into a consistent gridded record stretching back to 1979 (1981 for Alaska) right up to near the present.
How & where you'd use it. It provides the steady, long-term weather input that hydrologists and land-surface models need to study floods, droughts, and water supply over time.
What's measured
Coverage & cadence
- Time span— → ongoing
What you can do with it
- Map air pollutants — NO₂, aerosols, ozone
- Track greenhouse gases and Earth's energy budget
- Feed weather and air-quality analysis
Official description
Announcements: April 2, 2026: The Office of Water Prediction (OWP) has identified some brittle components of the AORC data processing pipelines that, by our estimations, have resulted in 0.04% of all available rows being incorrectly masked. We've resolved the issue and we are currently regenerating the Zarr files to ensure a complete record. We will post an updated announcement once the corrected data is posted. The Analysis Of Record for Calibration (AORC) is a gridded record of near-surface weather conditions covering the continental United States and Alaska and their hydrologically contributing areas. It is defined on a latitude/longitude spatial grid with a mesh length of 30 arc seconds (~800 m), and a temporal resolution of one hour. Elements include hourly total precipitation, temperature, specific humidity, terrain-level pressure, downward longwave and shortwave radiation, and west-east and south-north wind components. It spans the period from 1979 across the Continental U.S. (CONUS) and from 1981 across Alaska, to the near-present (at all locations). This suite of eight variables is sufficient to drive most land-surface and hydrologic models and is used as input to the National Water Model (NWM) retrospective simulation. While the native AORC process generates netCDF output, the data is post-processed to create a cloud optimized Zarr formatted equivalent for dissemination using cloud technology and infrastructure. **AORC Version 1.1 dataset creation** The AORC dataset was created after reviewing, identifying, and processing multiple large-scale, observation, and ana
Get the data
# NOAA Open Data on AWS — public S3, no login
import s3fs
fs = s3fs.S3FileSystem(anon=True)
# find this dataset's bucket in the docs link in the sidebar, then:
# files = fs.ls("noaa-<bucket>/...")
# open NetCDF/GRIB with xarray, COGs with rioxarrayNOAA Open Data is on public AWS S3 — no login at all (anonymous access).
Official links
- Open data source NOAA Open Data