Residents in the D.C. area should prepare for unseasonably warm and humid conditions, particularly on Friday when temperatures may reach 90°F (32.2°C). This heat could pose risks for outdoor activities, especially for vulnerable populations such as the elderly and those with pre-existing health conditions. The arrival of a cold front on Saturday may lead to periods of heavy rain, increasing the risk of localized flooding. Frost conditions are possible in areas like Shenandoah Valley and northern Maryland early next week (NBC Washington, 2026-09-29).