For the third straight day we reached 90 or higher in D.C. (making it officially a heat wave), and we should extend the streak to 5 by Sunday. But Sunday evening a cold front plows into the region, setting up the likelihood of showers and thunderstorms and then cooler weather.
Through Tonight: Enjoyable weather to be out and about thanks to comfortably warm temperatures, moderate humidity levels and a gentle, soft breeze from the south. Temperatures fall back through the 80s and 70s this evening with lows by early morning near 70 downtown and mid-60s in the cooler suburbs. Skies are partly cloudy to mostly clear.
Tomorrow and tomorrow night (Saturday): The first day of meteorological summer brings typically summer-like weather. Under partly cloudy skies and moderate to high humidity levels, highs reach into the low 90s. Overnight lows fall from the mid-60s in the cooler suburbs to the low 70s downtown. Winds are light from the south.
Sunday: Hot and fairly humid with cloud cover bubbling up in the afternoon. Any afternoon thunderstorms tend to be isolated (20 percent chance) around town, with a few more out towards the mountains (30 percent chance). The main thrust of storms arrives in the evening and overnight (60-70 percent chance), and some of them could be on the strong side. Check forecasts throughout the weekend for updates.
Pollen: Trees counts are MODERATE, grasses are HIGH, and weeds are LOW.
May 90+ degree streaks: The streak of 3 days at or above 90 to close out this month ties (with 12 other years) for the 9th longest 90+ streak on record during May. The longest streak of 90+ days during the month, dating back to the late 1800s, occurred in 1991 when seven such days lined up May 25-31. Full list via Southeast Regional Climate Center