Summer 2026 is expected to bring a volatile mix of heat, severe thunderstorms and flooding to the United States, with El Niño developing and flexing its influence on the weather pattern.
Where will it be a hot summer?
As AccuWeather reports, another hot summer is predicted across most of the contiguous United States in 2026, with almost no areas expected to have temperatures below the historical average for the season. The widespread heat will drive up energy demand and could lead to higher electric bills.
The worst of the heat will focus across parts of California, Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming, fueling a widespread fire threat. “Northwest, Great Basin wildfires can be destructive this summer, along with impressive heat waves and increasing drought conditions,” AccuWeather Meteorologist Brandon Buckingham said.
The heat will not be limited to the West. AccuWeather is predicting the number of 90-degree days to be near or above the historical average in Boston, Chicago, New York City and Philadelphia. In the Northeast, there could be a “late surge of heat and higher humidity,” according to AccuWeather Long-Range Expert Paul Pastelok. The added humidity will boost AccuWeather RealFeel® Temperatures during the day and contribute to warmer nights.
Where will there be Severe Weather Threats?
Severe weather is expected to be most active from early to midsummer across the Plains, Midwest and Ohio Valley, with the storms shifting farther east later in the season. “The number of tornadoes can run near to above average in June and July,” Pastelok said. “The numbers can drop off dramatically in August.” While the tornado threat could be lower, severe thunderstorms will persist through August.
In July and August, there will be a rising risk of destructive lines of thunderstorms known as derechos. A derecho is much more powerful than a typical thunderstorm and is sometimes called an “inland hurricane” because of the widespread wind damage it can cause. Winds can exceed 100 mph, strong enough to flatten cornfields and trigger power outages that last for days in the summer heat.
On June 20, 2025, intense thunderstorms broke out across North Dakota, spawning the first EF5 tornado in 12 years. That severe weather event also featured an intense derecho that raced across 800 miles in about 12 hours and unleashed winds up to 106 mph.
Floods vs. Drought
Summer thunderstorms could help ease drought concerns in the mid-Atlantic and parts of the central U.S., but they may also raise the risk of flash flooding, including in parts of the Texas Hill Country.
On July 4, 2025, deadly flash floods swept through Kerr County, Texas, resulting in more than 100 deaths, between $18 billion and $22 billion in economic damage and long-lasting impacts on the local community.
The Texas Hill Country is just one of several areas that face a flood risk this summer. “Flash flood events are expected in parts of the Plains, Mississippi Valley and Ohio Valley on a higher frequency this summer,” Pastelok said.
Flooding can also be a concern in the Southwest and southern Rockies when the North American monsoon ramps up and tropical moisture surges northward. In those areas, flash flooding and mudslides could lead to road closures, especially in burn scars and steep terrain.
While flooding is a concern in some parts of the country, drought is expected to worsen in others. Drought conditions are likely to expand across the Northwest and Northern California, and long dry stretches could also intensify drought along parts of the Gulf Coast and the southern and central Appalachians.
Monsoon Season Could Bring Relief (and Risk)
The North American monsoon is expected to be close to the historical average overall but will likely come in spurts throughout the season, according to AccuWeather Senior Meteorologist Chad Merrill.
Moisture could start to arrive near the end of June, which is slightly earlier than normal. That may bring some welcome relief to the Southwest after a hot, dry start to the summer. However, the monsoon may weaken or shift at times during July, leading to breaks in rainfall.
Tropical moisture from the eastern Pacific may also add to rainfall totals this year, including in parts of southern California and Nevada. That could help interrupt the dry season at times, but it may also bring flash flooding, mudslides and even dry thunderstorms with lightning strikes that ignite new fires.
Any monsoon rain will be welcome across the Southwest following a winter with little snowfall in the mountains. Rain could bring some short-term relief to the Colorado River Basin and help feed into Lake Mead and Lake Powell, which are both facing some of the lowest water levels since their construction.
A “Super” El Niño will Shape the Summer Pattern
A “Super” El Niño is expected to develop early in the summer and will have a growing influence on the tropics and the broader weather pattern across the United States through the rest of 2026.
The large-scale climate pattern is linked to ocean temperatures near the equator of the Pacific Ocean. When sea surface temperature anomalies over a particular area of the east-central Equatorial Pacific are at least 0.5 of a degree Celsius (0.9 of a degree Fahrenheit) above long-term historical averages, an El Niño is born.
A developing El Niño should help boost tropical activity in the eastern Pacific while keeping the Atlantic season near to below average overall. “Other impacts this summer can be wetter conditions across the central Plains, Mississippi Valley and Ohio Valley,” Pastelok explained. “Temperatures can heat up quickly in the Northwest with drier conditions as well. Severe weather can pick up in June and July with near- to above-average tornadoes from the Plains to the East Coast.”
El Niño is forecast to strengthen and could evolve into a rare “super El Niño” later in 2026 when it could have bigger impacts on the weather across the United States in the final months of 2026 and the start of 2027.
The Bottom Line
•The hottest weather compared to average will focus on the West and Northwest.
•Severe weather is expected to be most active in June and July from the Plains to the Midwest and Ohio Valley.
•The flooding zone to watch most closely runs from Texas to the Ohio Valley, including the area of the Texas Hill Country that was devastated in 2025.
•The monsoon may bring some relief to the Southwest, but it could also trigger flash flooding, mudslides and lightning-sparked fires.
•Drought is expected to worsen in the Northwest, Northern California and parts of the Gulf Coast and Southeast.
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