Summer Heat Persists in the U.S. Thanks to El Niño
A powerful El Niño and climate change are keeping the U.S. in a heat wave that began early in the year, with many regions expecting temperatures 5–10°F above normal through September. Record highs and nights have shattered long‑standing marks, and experts warn the heat may linger into fall.
By Felo News Desk · Published
Early summer in the United States was nothing short of extraordinary. By July, temperatures across the country were already pushing the limits of what most people had experienced in recent memory. Now, as the calendar flips to September, the heat shows no sign of easing. Meteorologists say that a combination of a strong El Niño and the ongoing effects of climate change are keeping the heat wave alive.
What’s Causing the Extended Heat?
The U.S. Climate Prediction Center has forecast that much of the country will continue to see temperatures above normal through at least the end of September. The models point to a pronounced ridge pattern—a high‑pressure system that traps warm air and prevents cooler air from moving in. This atmospheric arrangement is a hallmark of a robust El Niño, which brings warmer-than-average waters to the eastern Pacific and reshapes weather patterns across the globe.
Climate change, meanwhile, raises the baseline for extreme heat. As average temperatures climb, the threshold for what counts as a “heat wave” shifts upward, making even moderate temperatures feel oppressive. Nights, in particular, have become less forgiving; the lack of cooling overnight means that heat stress can accumulate, putting vulnerable populations at higher risk.
Record‑Breaking Temperatures and Their Impact
Throughout 2026, the United States has seen nearly 44,000 record daytime highs and more than 53,000 record‑high overnight lows. These numbers include many records that date back over a century. For example, Salt Lake City recorded 109 °F on July 12—its highest temperature on record since 1874—while Washington, D.C., tied its all‑time warmest overnight low of 84 °F on July 3, a mark that has stood since 1871.
Even regions that usually escape extreme heat have been affected. Southern California, for instance, issued excessive heat warnings during the second week of September. The combination of hot days and humid air turned familiar streets into a “Bourbon Street” of sweat.
What’s Next for the Heat Wave?
While September highs may not reach the blistering peaks of July, many areas will still experience summer‑like temperatures. Forecasts suggest that the Upper Midwest and the Deep South could see temperatures 5–10 °F above normal in the latter half of the month. The lingering El Niño is expected to continue influencing weather patterns well into the fall and winter, potentially keeping the U.S. in a state of above‑normal warmth for months to come.
Scientists warn that if the heat persists, more records will be broken. The combination of a strong El Niño and a warming planet creates a perfect storm for prolonged heat events, making it essential for communities to prepare for extended periods of discomfort and risk.
Key facts
- El Niño and climate change are extending U.S. heat waves
- Record highs and nights have shattered long‑standing temperature records
- Heat warnings have reached even typically cooler regions
- Forecasts predict 5–10 °F above‑normal temperatures in key areas
- The heat wave may persist into fall and winter
Why it matters
Prolonged heat waves strain public health systems, increase energy consumption, and threaten vulnerable populations. Understanding the underlying causes helps communities prepare and adapt.
Frequently asked questions
What is El Niño?
El Niño is a climate pattern characterized by warmer than normal sea surface temperatures in the central and eastern Pacific Ocean, which can alter weather worldwide.
How does climate change affect heat waves?
Rising average temperatures raise the baseline for extreme heat, making even moderate temperatures feel more intense and reducing nighttime cooling.
What can residents do to stay safe?
Stay hydrated, avoid outdoor activity during peak heat, use air conditioning or fans, and check on vulnerable neighbors.
Sources
- [1] wired.com — originally reported as “It Still Feels Like Summer in Parts of the US. Blame El Niño”
