Seattle logged its hottest day of 2025 on Wednesday when the temperature reached 94°F, according to the National Weather Service, topping the previous annual high of 92°F set earlier in the afternoon. A Heat Advisory covering parts of western Washington has been extended through 5 p.m. Thursday, and a Red Flag Warning remains in effect for higher–elevation areas of the Cascades, where hot, dry conditions have elevated wildfire risk. Forecasters expect Puget Sound highs to fall back into the 80s by the weekend. The same heat dome pushing Pacific Northwest readings into the 90s is also broiling the Mid-Atlantic and Northeast. Washington, D.C., along with portions of Maryland and northern Virginia, is under a Heat Advisory from 11 a.m. to 8 p.m. Thursday, when air temperatures in the mid-90s are forecast to produce heat-index values of 100–105°F. New York City and surrounding counties face a similar advisory through 10 p.m., with feels-like temperatures between 95°F and 100°F, while the Philadelphia region is on a NEXT Weather Alert for heat indices that could also approach 105°F. The National Weather Service is urging residents in all affected areas to limit outdoor activity, stay hydrated and check on vulnerable neighbors. Isolated late-day thunderstorms are possible along the I-95 corridor, but broader relief is not expected until a weak cold front lowers humidity levels heading into the weekend.