July Was Hottest Month On Record in Contiguous US: NOAA

The contiguous United States recorded its hottest July since recordkeeping began, according to data released by the National Oceanic and Atmospheric Administration (NOAA). Record-breaking overnight temperatures were a key factor in pushing the month past previous highs.

NOAA reported an average temperature of 76.9 degrees Fahrenheit across the lower 48 states and Washington, D.C., surpassing the previous record set in July 1936 and matched again in July 2012 by approximately 0.1 to 0.2 degrees. Federal temperature records date back to 1895.

Daytime temperatures reached 89.5 degrees Fahrenheit on average, ranking as the sixth-hottest on record for daytime maximum temperatures. Overnight lows, however, set a new record at an average of 64.2 degrees Fahrenheit - 3.7 degrees above the historical average. This exceeded the previous record from July 2022 by 0.7 degrees.

An analysis by Climate Central using data from 1970 to 2024 linked increasingly warmer summer nights across the United States to climate change.

Outside the contiguous states, Alaska recorded temperatures 0.9 degrees below its long-term average from 1925 through 2000, while Hawaii finished 0.6 degrees warmer than its 1991-2020 average.

NOAA noted "much-above-average" Temperatures across the interior West, Southwest, Rocky Mountains, northern Plains, upper Midwest, and portions of the Gulf Coast and Southeast. Thirteen states experienced one of their five warmest Julys on record, with Wyoming setting an all-time July record at 0.9 degrees above its previous high.

The extreme heat coincided with unusually dry conditions across much of the northern Rockies, northern Plains, upper Midwest, Northeast, southern Plains, Mississippi Valley, central Gulf Coast, and Southeast. Other regions saw the opposite pattern, with above-average rainfall in parts of the West, Southwest, central Plains, and upper Midwest.

As of Tuesday, the U.S. Drought Monitor reported approximately 48.5% of the contiguous United States and Washington, D.C., in drought conditions. More than two-thirds of Puerto Rico also faced drought.