Table 1:

Overview of the Meteorological Datasets Used in the Analysis

	First-Order Stations (ISD-Lite)	USCRN Stations	PRISM	Daymet
Spatial Coverage	274 stations in the US, located primarily at airports	137 stations in the US, located at sites minimally affected by anthropogenic land uses	Conterminous United States (CONUS) at horizontal spatial resolution of 4 km or 800 m	North America at horizontal spatial resolution of 1 km
Temporal Coverage	Hourly or sub-hourly observations over the past several decades	Sub-hourly observations since as early as 2000	Daily from 1981 to six months prior to present	Daily since 1980; updated annually
Day Definition	00:00 – 23:59 UTC	00:00 – 23:59 UTC	12:01 UTC on day i-1 - 12:00 UTC on day i	00:00 – 23:59 UTC
Meteorological Variables Reported	Temperature Dew-point T Precipitation Atm. Pressure Wind Cloud cover	Temperature Relative humidity Precipitation Solar radiation IR surface T	Tmin, Tmax, Tmean TDmean VPDmin, VPDmax Precipitation	Tmin, Tmax VPmean Precipitation Solar radiation Snow-water eq. Day length
User-Derived Variables	Heat index Relative humidity Absolute humidity	Heat index Absolute humidity	HImin, Hmax, HImean RHmin, RHmax, RHmean AHmean	Tmean HImax, HImean RHmin, RHmean AHmean

Table 1: Abbreviations: minimum, maximum, and mean temperature (T_min, T_max, and T_mean); mean vapor pressure (VP_mean); minimum and maximum vapor-pressure deficits (VPD_min and VPD_max); minimum, maximum, and mean relative humidity (RH_min, RH_max, and RH_mean); mean absolute humidity (AH_mean); and minimum, maximum, and mean heat index (HI_min, HI_max, and HI_mean).