A stretch of extreme summer heat and humidity will grip the Baltimore region through the middle of next week, with the possibility of disruptive and at times dangerous weather conditions during the afternoon and evening hours.

The heat index values Friday are expected to exceed 105 degrees in many areas in Central Maryland. Actual air temperatures will climb into the upper 90s to near 100°, but stifling humidity will make it feel significantly hotter, especially in urban corridors like downtown Baltimore, Columbia, and Essex. The excessive heat will strain infrastructure, increase the risk of heat-related illness, and pose challenges for outdoor workers and vulnerable populations.

Isolated strong to severe thunderstorms will develop during the peak heat of the afternoon across Western Maryland and then slowly make their way toward the Baltimore area. Some of the strongest storms may produce damaging winds, torrential downpours, and intense cloud-to-ground lightning. The timeline for storms appears to be 4 p.m. until 10 p.m.

Weekend looks steamy and stormy at times across Maryland

Saturday’s high temperatures won’t be as extreme as Friday’s, but higher humidity levels will mean little “relief.” Heat index values will approach 100 degrees by midday, with another round of scattered afternoon and evening storms. While not everyone will see rainfall, those who do may experience locally heavy rain and gusty winds.

By Sunday, storm coverage will likely increase slightly, especially by late afternoon and evening. Highs will hover near 90 degrees, though high humidity will once again push heat index values into the upper 90s. The scattered nature of the storms means that some neighborhoods could remain dry while others deal with intense downbursts or brief flooding.

Maryland heat wave continues through Wednesday

Monday will feature a brief lull in storm activity, but the heat will keep cranking. By Tuesday, temperatures are expected to spike again, reaching the mid to upper 90s, with humidity pushing the heat index back into the 100-105-degree range.

By Wednesday, a stronger cold front will approach the region, bringing yet another chance for strong to severe thunderstorms — potentially more widespread than earlier in the week. The front will also usher in a refreshing air mass.

Thursday will feel dramatically different. High temperatures will tumble into the low 80s, and much of the region will enjoy overnight lows in the 60s, particularly in the suburbs. A reinforcing shot of cooler and drier air will approach us from the northwest Thursday afternoon, which may spark another brief, but gusty shower or thunderstorm.

City pools will operate on a modified schedule starting Friday through Sunday, according to the Baltimore City Department of Recreation and Parks. Most park pools will be open from 11 a.m. through 8 p.m., with 30-minutes temporary closures through the afternoon. The Riverside pool will close at 3 p.m.

Neighborhood pools will be open from noon to 7 p.m. over the weekend. All city pools will be open Monday and Tuesday from noon to 7 p.m., including pools that are usually closed during those days.