The Warmest Day of the Year in The United States
We tend to connect “summer” with “hot” due to obvious reasons. For most of the U.S., the warmest conditions during the meteorological summer months in the Northern Hemisphere (June, July, and August) are observed. However, it is worth noting that the “hottest day of the year” from a climatological perspective differs significantly throughout the United States. Its occurrence can range from early June in certain regions to as late as September and October in others!
To help you identify the hottest time of year in your region, NCEI has collaborated with NOAA Climate.gov to create “Warmest Day of the Year” maps for the United States.
The maps are based on NCEI’s 30-year averages of climatological variables, including average high temperatures by day, derived from its 1991–2020 U.S. Climate Normals. Scientists can identify the warmest day of the year by analyzing these smoothed values and determining the day with the highest maximum temperature normal.
