Monthly Attribution Overview – October 2025

In October 2025, the United States experienced an average temperature anomaly of 2.0°F across 192 analyzed cities, with the Ohio Valley seeing the most unusual heat at 4.89°F above normal. Fairbanks, AK, recorded the highest individual city anomaly at 7.1°F. Long-term data indicates that 190 of 191 analyzed stations have shown positive warming trends since 1970, with Wheeling, WV, experiencing the fastest increase at 7.8°F. Climate change influence was particularly strong in San Juan, PR, which had 29 days at a Climate Shift Index (CSI) of 5, and Honolulu, HI, where both cities saw at least two weeks of CSI values of 2 or higher.

• Across 192 analyzed cities in the U.S., the average temperature anomaly for October 2025 was 2.0°F, with 150 of those cities recording hotter-than-average temperatures.
• The Ohio Valley region experienced the most unusual heat in October 2025, with an average temperature anomaly of 4.89°F. Conversely, the West region had the smallest difference from normal, being 0.5°F cooler than average.
• Long-term warming trends since 1970 are evident in 190 out of 191 analyzed ACIS stations. Wheeling, WV, showed the most significant warming, with its average October temperature increasing by 7.8°F since 1970.
• Climate change significantly influenced temperatures in specific locations: San Juan, PR, had 29 days in October with a Climate Shift Index (CSI) of 5, meaning temperatures were at least five times more likely due to climate change. Both San Juan and Honolulu, HI, experienced at least two weeks of CSI values of 2 or higher.

APA

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

Chicago

Climate Central. Monthly Attribution Overview – October 2025. 2025. https://www.climatecentral.org/report/monthly-attribution-overview-october-2025.

Wikipedia

{{cite report |author=Climate Central |title=Monthly Attribution Overview – October 2025 |date=4 November 2025 |url=https://www.climatecentral.org/report/monthly-attribution-overview-october-2025 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

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