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D.C. area forecast: Still sweaty with storms around

1:45 p.m. update: With the very high levels of humidity, storms are flaring up around the region and will likely pulse up and down through around sunset. They’ll be hit or miss, but you may wish to keep an umbrella handy.

Original post from 5 a.m.

A somewhat subjective rating of the day’s weather, on a scale of 0 to 10.

6/10: Summer steam is in full swing — could be our sixth 90-degree day in a row — still with a slight storm threat.


Today: Partly sunny, humid. Isolated p.m. storm? Highs: Low 90s.
Tonight: Muggy, isolated evening storm? Lows: 70s.
Tomorrow: Hot and humid. Chance of p.m. storms. Highs: Low-to-mid-90s.


For those of us still in town, this is the kind of sweaty mid-summer week that builds character in Washingtonians young and old. It’s hot today and hotter tomorrow, but not the excessive heat we can easily get this time of year. With the high humidity, though, the heat index is in triple-digit territory today and tomorrow, before edging back a bit starting Friday. Tomorrow afternoon into evening presents the best chance of showers and storms through the forecast period.

Today (Wednesday): Heat and high humidity combine with partly sunny skies (once we burn off patchy morning fog) for a classic late-July “steamer.” The heat part could be worse, with highs hitting the fairly typical low 90s. But with a muggy light breeze from the south keeping dew points up in the low 70s, the afternoon heat index peaks near or past 100. Most shower and storm activity should be confined to the mountains out west, but can’t rule out an isolated shower or storm around here during the late afternoon or evening. Confidence: Medium-High

Tonight: We’ll hold on to an isolated storm risk through the evening. The main story though is the mugginess and stagnant air, as lows stay up in the 70s area-wide. Confidence: Medium-High

For related traffic news, check out Dr. Gridlock. Keep reading for the forecast through the weekend…

Tomorrow (Thursday): Highs head for the low-to-mid-90s with the high humidity still locked in place. Increasing afternoon clouds should keep the heat from edging into the extreme range, though a heat index in the 100-105 range seems bad enough. About a 50 percent chance we see a line or two of showers and storms come through during the afternoon into evening, courtesy of an approaching cold front. If so, some storms could be quite heavy. Confidence: Medium

Tomorrow night: Evening storm chances remain in the 50 percent range, before decreasing overnight as the cold front clears the area. Overnight lows settle back to near 70 to the mid-70s, as skies see partial clearing and somewhat drier air tries to work its way in. Confidence: Medium


Friday, Saturday and Sunday all look like similar days with partly to mostly sunny skies, highs mainly in the low 90s, and humidity down a bit to the moderate range. As of now, no major threats for showers or storms, though I wouldn’t rule out an isolated shower early Friday, Saturday evening or Sunday evening. Confidence: Medium