Over 70 million Americans experienced the muggiest first two months of summer on record due to climate change in the Eastern United States. The humidity in the region has increased significantly, with dew points reaching 65 degrees Fahrenheit or higher in June and July. The National Weather Service reported that parts of 27 states and Washington, D.C. had record-breaking days with average daily dew points of 65 degrees Fahrenheit or higher. The humidity in the East has also increased, with Philadelphia, Washington, and Baltimore experiencing scorching dew points of at least 75 degrees.
Dew points are a measure of moisture in the air expressed in degrees, and the summer of 2025 has had dew points that average at least 6 degrees higher than the 1951-2020 normals in Washington, Baltimore, Pittsburgh, Richmond, Columbus, and St. Louis. The average June and July humidity for the entire country east of the Rockies rose to more than 66 degrees, higher than any year since 1950.
High humidity and heat feed on each other, with the atmosphere holding an extra 4% more water for every degree Fahrenheit (7% for every degree Celsius) warmer it gets. The Midwest and East experienced hot high pressure systems and heavy rain, with the occasional cool front providing relief in August.
