Data: U.S. Summer Temperature Trends

Please click here to download local temperature trend data for 240+ U.S. locations.

This dataset supports U.S., state-, and county-level charts downloadable from this page.
Embeddable interactive maps and custom data views are available here through Observable
Click here for a KML map download
For background on these trends, their connections to climate change, and their local impacts, click here for the most recent summer package from Climate Matters.

METHODOLOGY

Average temperatures and days above normal were calculated for each meteorological summer (June, July, August) from 1970 to 2024 using data obtained from the Applied Climate Information System, which is developed, maintained, and operated by NOAA’s Regional Climate Centers. Summer days above normal were defined as the number of days with average temperatures above the 1991-2020 NOAA/NCEI climate normal.

Average monthly temperatures for U.S. counties were obtained from NOAA/NCEI’s Climate at a Glance. The change in annual average summer temperatures from 1970-2024 was calculated using linear regression.

Climate Central's local analyses include 247 U.S. weather stations. For reported data summaries of historical (1970-2024) observed summer warming trends based on linear regression, however, only 242 stations are included due to data completeness measures that were not met by five stations: Bend, Ore.; Hazard, Ky.; Jefferson City, Mo.; Twin Falls, Idaho; and Wheeling, W.Va.

This Climate Matters analysis is based on open access data from the National Oceanic and Atmospheric Administration (NOAA).