Monthly Attribution Overview May 2025

The report analyzes May 2025 temperatures across 192 U.S. cities, finding a moderate average anomaly of 0.1°F. While 102 cities were cooler than average, 24 recorded top 10 warmest May temperatures. Long-term trends show 185 of 191 analyzed stations have warmed since 1970, with Reno, Nevada, seeing the fastest increase. The Climate Shift Index (CSI) highlighted strong climate change influence in 35 cities, particularly in the West, South, and Southeast.

• In May 2025, the United States experienced generally moderate temperatures, with an average anomaly of 0.1°F across 192 analyzed cities. A slight majority of 102 cities were cooler than average, while 24 cities (12% of stations) recorded one of their top 10 warmest May monthly temperatures on record.
• Long-term data indicates widespread warming since 1970, with 185 out of 191 ACIS stations showing positive temperature trends for May. Reno, Nevada, experienced the most significant warming, with its average May temperature increasing by 7.2°F since 1970.
• The Climate Shift Index (CSI) indicated a strong climate change influence in 35 cities that experienced at least one week of CSI values of 2 or higher. The highest number of days with a CSI of 2 or above (averaging 7.2 days) occurred in cities in the West.
• San Antonio, TX, was identified as the most unusually warm city in May 2025, recording a temperature 3.98°F warmer than usual.
• The report notes that a city can have a negative temperature anomaly relative to recent norms (1991–2020) while still showing a high CSI, as the CSI compares conditions to pre-industrial times. This was observed in San Juan, which was cooler than the recent average but significantly warmer than a typical pre-industrial May.

APA

Climate Central (2025). Monthly Attribution Overview May 2025. https://www.climatecentral.org/report/monthly-attribution-overview-may-2025

Chicago

Climate Central. Monthly Attribution Overview May 2025. 2025. https://www.climatecentral.org/report/monthly-attribution-overview-may-2025.

Wikipedia

{{cite report |author=Climate Central |title=Monthly Attribution Overview May 2025 |date=2 June 2025 |url=https://www.climatecentral.org/report/monthly-attribution-overview-may-2025 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025monthly, author = {{Climate Central}}, title = {{Monthly Attribution Overview May 2025}}, institution = {Climate Central}, year = {2025}, month = jun, url = {https://www.climatecentral.org/report/monthly-attribution-overview-may-2025}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }