5:30 p.m.: D.C. has broken its record high for the date, with National Airport reaching a high of 102 at 3:38 p.m. That breaks the previous record for the date of 101 in 1991. Baltimore (BWI) also reached 102, tying its record for the date from 1991. 99 was indeed the official high at Dulles, which ties the record high for the date also from 1991.
5:05 p.m.: The heat has been terrible again today, though thankfully the humidity has been lower than yesterday so the heat index has been more forgiving - to around 110 compared to Friday’s 120+. So far, no storms have affected the immediate metro area. Radar is pretty quiet at the moment, but a few strong storms could still develop in spots into this evening.
Here’s today’s latest record round-up for the area:
National Airport has reached at least 101 degrees today, which ties the record high for the date from 1991. D.C. has now had back -to-back 100-degree days two straight years (last year was July 6-7). Also, the morning low of 84 would tie the all-time warmest low on record - 84 on July 16, 1983 - unless a thunderstorm knocks the temperature lower than that before midnight.
Dulles has also tied its record high for the date, reaching at least 99 so far (last time it reached 99 on this date was in 1991). The airport’s morning low of 76 would break the previous record warm low for the date - 73 in 1978 - assuming a t’storm doesn’t cool temps lower than that before midnight.
BWI has reached at least 101 today. Record for the date is 102 (in 1991). Will have to see if the sensor might have hit 102 or higher between hourly observations this afternoon.
The heat continues tomorrow though not quite as bad (heat index around 105 compared to today’s ~110), thus a Heat Advisory in effect tomorrow noon to 8 p.m. rather than the more serious Excessive Heat Warning that remains in effect today until 8 p.m. See Ian Livingston’s full forecast into the coming work week.