Weather / U.S.
National weather forecast with regional outlook and marine hazards
Heat continues through midweek before a frontal system brings thunderstorms and cooler air to the Northeast by Friday.
The National Weather Service is tracking a significant atmospheric pattern shift across North America this week, with tropical remnants moving inland from the Gulf of Mexico while a cool high-pressure system develops over the Great Lakes. Much of the eastern half of the country will experience above-average warmth through midweek, with temperatures reaching the mid-90s across the South and mid-Atlantic. By Friday, a frontal system will begin to introduce cooler, drier air into the northeast, bringing relief to areas experiencing heat stress. The West Coast remains dry with continued high pressure building from the Pacific.
Northeast & New England
Forecasters in Boston predict partly cloudy skies through Thursday with highs near 88 degrees Fahrenheit. Humidity levels will remain elevated due to tropical moisture moving northward, making it feel closer to 95 degrees during afternoon hours. Overnight lows will settle into the mid-70s. Friday's forecast calls for scattered thunderstorms moving through as a cold front approaches, with potential heavy rainfall in areas from western New York through New England. The Pioneer Valley can expect 1 to 3 inches of rain Friday evening through Saturday morning, with the heaviest rainfall expected between 7 p.m. and midnight Friday. By Sunday, cooler and drier air will dominate, with highs only reaching the low 70s and clearing skies returning by afternoon.
Mid-Atlantic & Southeast
Washington, D.C., Baltimore, and Philadelphia will see heat index values reaching 98 to 102 degrees through Thursday as tropical moisture combines with high temperatures. Heat advisories remain in effect for much of Virginia and the Carolinas. Charlotte, North Carolina is forecast to reach 94 degrees on Wednesday, with only slight moderation Thursday before Friday's frontal system brings showers and thunderstorms. Richmond is under a slight risk for severe weather Friday afternoon, with gusty winds and isolated large hail possible ahead of the advancing cold front. Atlanta and the deeper South will remain hot and humid with scattered afternoon thunderstorms possible through midweek, with moisture from Tropical Storm Marcus (now downgraded) continuing to enhance rain chances.
Midwest & Great Plains
Chicago expects continued heat through midweek with highs near 91 degrees, though afternoon thunderstorms Wednesday evening could bring localized rainfall of 0.5 to 1 inch. Kansas City will experience similar conditions, with the greatest rain potential Wednesday and Thursday evenings as the tropical system moves inland. By Friday, cooler air begins flowing southward from Canada, dropping temperatures into the 70s by Saturday morning across the central Great Lakes and Ohio Valley. The Northern Plains remain dry with sunny skies and highs in the 80s.
Western United States
The West Coast remains dominated by high pressure, bringing sunny skies and warm temperatures throughout the period. Los Angeles expects highs near 84 degrees with very light winds. San Francisco will see typical late August weather with highs near 72 and afternoon fog. Phoenix continues its heat wave with highs near 113 degrees, with dangerous heat index conditions expected to last through Saturday. The Pacific Northwest, from Seattle northward through Vancouver, remains cool and dry with highs in the 70s and abundant sunshine. No significant weather systems are expected to affect the West through the end of next week.
Marine & Coastal Hazards
Small craft advisories remain in effect along the Atlantic Coast from Massachusetts south through the Carolinas, with winds gusting to 20 to 25 knots and waves building to 4 to 6 feet. Rip current risks are elevated along Atlantic beaches due to tropical influence and higher than normal water temperatures. Swimmers should exercise caution and pay attention to local beach warnings. The Gulf of Mexico coast near Louisiana and Texas may see locally strong winds Thursday, with 15 to 20 knot winds and 3 to 5 foot waves possible near the coast.
For the most up-to-date forecasts and severe weather alerts, visit weather.gov or download the National Weather Service mobile app. Local television weather forecasters and your county Emergency Management office also provide detailed forecasts. For weather-related emergency assistance, contact your local emergency services.