Heat Index Values could rech over 100 degrees.
District of Columbia-Frederick MD-Carroll-Northern Baltimore-Cecil-Southern Baltimore-Prince Georges-Anne Arundel-Charles-St.Marys-Calvert-Northwest Montgomery-Central and SoutheastMontgomery-Northwest Howard-Central and Southeast Howard-Northwest Harford-Southeast Harford-Fairfax-Arlington/FallsChurch/Alexandria-Stafford-Spotsylvania-King George-SouthernFauquier-Western Loudoun-Eastern Loudoun-Northwest Prince William-Central and Southeast Prince William/Manassas/Manassas Park-937 AM EDT Mon Jun 23 2025...EXTREME HEAT WARNING REMAINS IN EFFECT UNTIL 9 PM EDT THISEVENING......EXTREME HEAT WARNING IN EFFECT FROM 11 AM TO 9 PM EDT TUESDAY...* WHAT...For the first Extreme Heat Warning, dangerously hot conditions with heat index values up to 110 expected. For the second Extreme Heat Warning, dangerously hot conditions with heat index values up to 110 expected.* WHERE...Portions of DC, central, north central, northeast, northern, and southern Maryland, and central and northern Virginia.* WHEN...For the first Extreme Heat Warning, until 9 PM EDT this evening. For the second Extreme Heat Warning, from 11 AM to 9 PM EDT Tuesday.* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.PRECAUTIONARY/PREPAREDNESS ACTIONS...Drink plenty of fluids, stay in an air-conditioned room, stay out ofthe sun, and check up on relatives and neighbors.Do not leave young children and pets in unattended vehicles. Carinteriors will reach lethal temperatures in a matter of minutes.By The National Weather Service, Sterling, Va.