Daymet provides long-term, continuous, gridded estimates of daily weather and climatology variables by interpolating and extrapolating ground-based observations through statistical modeling techniques. The Daymet data products provide driver data for biogeochemical terrestrial modeling and have myriad applications in many Earth science, natural resource, biodiversity, and agricultural research areas. Daymet weather variables include daily minimum and maximum temperature, precipitation, vapor pressure, shortwave radiation, snow water equivalent, and day length produced on a 1 km x 1 km gridded surface over continental North America and Hawaii from 1980 and over Puerto Rico from 1950 through the end of the most recent full calendar year.
Daymet is a research product of the Environmental Sciences Division at Oak Ridge National Laboratory, Oak Ridge, TN. Daymet is supported by NASA through the Earth Science Data and Information System ( ESDIS ) and the TE Program. The continued development of the Daymet algorithm and processing is also supported by the Office of Biological and Environmental Research within the U.S. Department of Energy's Office of Science.
Daymet Version 4 is available as of December 15, 2020, through all delivery methods on the Get Data page. Version 3 data are still available for a short time only through Direct Download, THREDDS, and SDAT.
The Daymet Version 4 methodology and dataset is described in Thornton, P.E. et al., 2020 Developments in a daily gridded meteorological data set for North America -- Daymet Version 4, Submitted Manuscript.