Daymet is a computer program that uses observations from ground weather stations to estimate weather conditions at locations that are not instrumented. Output from the Daymet model includes Daily Maximum Air Temperature: a gridded data set of daily maximum temperature (℃) for every 1-km x 1-km pixel within the mapped spatial extent; currently North America, Hawaii, Puerto Rico and Bermuda. Within the Daymet algorithm, each pixel in the continuous gridded coverage is estimated by interpolating from a sample of surrounding ground weather stations that record local 24-hr daily weather values, including daily maximum temperature. A digital elevation model (DEM) is also used in the temperature estimation to take into account temperature variation in elevation. There are between 9,000 to 10,000 weather stations, depending on the year, in North America that are archived by the National Oceanic and Atmospheric Administration (NOAA) that record daily temperature variables.

Daymet data products are used within a variety of studies that require daily continuous temperature data including, but not limited to, crop modelling, forest production, vector borne illnesses, and climate change adaptation.

References: Daymet Data Set Home Page