Washington is waking up in a sauna. It is already steamy in the District this morning and temperatures are set to top out near 102 degrees on Saturday, July 4, with heat index values possibly pushing into the 110s. Skies start mostly clear, but scattered showers and thunderstorms, some strong to severe, are likely from late afternoon into the evening. The National Weather Service has placed the city under an Extreme Heat Warning through the evening, and the metropolitan region is under an air-quality alert. Overnight will not offer much relief, with lows only dipping into the mid 70s to low 80s.
What To Expect Today
Temperatures should peak near 102 degrees with west winds shifting to the southwest and humidity ticking up by midafternoon. Heat index values could climb into the 110s. According to the National Weather Service, an Extreme Heat Warning is in effect from 10 a.m. to 9 p.m., and scattered showers and thunderstorms are most likely between about 3 p.m. and 5 p.m., with additional chances into the evening. Hydration, shade and air-conditioned spaces are the name of the game during the warning period.
Afternoon Storm Risk
Storms may roll through in multiple rounds this afternoon and evening. Stronger cells could bring damaging straight-line winds and brief heavy downpours. That means neighborhood fireworks and backyard gatherings may be interrupted or cut short by lightning, strong gusts or localized flooding.
If you have outdoor plans, know where you can seek shelter quickly and keep a reliable, battery-powered alert source handy. Boaters and anyone on area rivers should be ready for storms that can develop suddenly over the water.
Air Quality And Health
The metro area is under a Code Purple air-quality alert for July 4, signaling very unhealthy pollution levels and advising residents to limit prolonged outdoor activity. The MWCOG air-quality forecast recommends that everyone, especially older adults, children and people with respiratory conditions, avoid extended exertion outdoors today.
When you stack poor air quality on top of intense heat, health risks climb quickly. Keep medications close, check on vulnerable neighbors and consider moving events indoors when possible.
Where To Cool Off
The District opens cooling centers during periods of extreme heat. If you do not have air conditioning, call 311 or check city resources for cooling center locations and hours. Wherever you are headed, carry water, wear light, loose-fitting clothing and never leave children or pets in parked vehicles, even for a short time.
Transit riders should expect warm stations and trains, allow extra travel time and think about avoiding the hottest hours of the day when possible.
Bottom Line
Plan your Independence Day around the heat first, and everything else second. Avoid strenuous activity during the midday peak and have a backup plan for evening celebrations in case storms move in. The Extreme Heat Warning runs through 9 p.m., and unsettled conditions are expected to continue into Sunday.
