Posted originally published at 2:28 p.m., updated at 4:36 p.m.


D,.C. skyline May 9, 2015. (Razan Altiraifi via Flickr)

Today marks the 10th straight day of 80-degree weather in Washington, D.C., a streak unprecedented in the first half of May in modern records (which date back to 1872).


(Southeast Regional Climate Center)

The stretch of summer weather commenced on May 3 when the mercury soared to 84 and has continued, without interruption, through today:

May 3: 84
May 4: 84
May 5: 86
May 6: 83
May 7: 81
May 8: 84
May 9: 83
May 10: 85
May 11: 83
May 12: 90

The 10 straight days at or above 80 is not only the longest such streak on record in the first half of May but also ties 1930 and 1944 for the most total 80+ degree days in the month’s opening two weeks.

Years with most days at 80 or higher in the first two weeks; 2015 not shown but has 10. (Southeast Regional Climate Center)
Years with most days at 80 or higher in the first two weeks; 2015 not shown but has 10. (Southeast Regional Climate Center)

This historic warm stretch has boosted the May’s average temperature to over 8 degrees above normal.

Today’s high temperature, the hottest of the year to date, puts an exclamation mark on the streak. We hit 90 for the first time this calendar year, 5 days ahead of the 30-year average first date of May 17.

But much cooler air streams into the region tonight with temperatures falling 30-40 degrees by Wednesday morning, when lows range through the 50s across the region.


GFS model forecast lows Wednesday morning (WeatherBell.com)

Highs on Wednesday only reach around 70, about 20 degrees cooler than the day before and ending our streak of summery weather.

Thursday also pleases those yearning for more springlike temperatures – with highs 70-75. But we pop back to near 80 or higher by the weekend and early next week.


GFS ensemble mean forecast for next 16 days (WeatherBell.com)

Since the start of May, summer has been the dominating force and, the hiccup Wednesday and Thursday aside, shows no sign of relenting.