Trick-or-treat weather has gotten warmer in most of the US: See the map

Climate change is taking some of the chill out of Halloween, according to a new analysis from Climate Central.

According to the climate research organization, October nighttime temperatures have been rising across most major U.S. cities over the past five decades, 

Halloween has gotten warmer over the decades

Big picture view:

Climate Central analyzed October nighttime temperatures in 246 U.S. cities from 1970 to 2025 and found that 93% of them experienced warming during that period.

Across the 228 cities where temperatures increased, October nights warmed by an average of 3.4 degrees Fahrenheit.

Cities in the Northeast saw the greatest regional warming, with October nighttime temperatures rising by an average of 4.1 degrees.

Reno, Nevada sees largest increase in temperatures

Dig deeper:

The five cities with the largest increases were Reno, Nevada, which warmed by 11.9 degrees, followed by El Paso, Texas, at 10.1 degrees; Las Vegas, Nevada, at 9.5 degrees; Tyler, Texas, at 8.3 degrees; and New Orleans, Louisiana, at 8.1 degrees.

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While temperatures have risen in most of the cities studied, 18 cities did not experience an overall warming trend in October nighttime temperatures during the period analyzed.

The findings are based on average annual minimum temperatures for October collected from 1970 through 2025. The analysis examined long-term temperature trends using statistical regression to compare changes over time.

The Source: Climate Central obtained the data on Oct. 1, 2026, from the Applied Climate Information System, which is operated by the National Oceanic and Atmospheric Administration's Regional Climate Centers. This story was reported from Los Angeles.