August, and summer, are history
Almost unnoticed as we all focused on Ernesto, the (meteorological) summer ended at midnight last night, along with the month of August. Here's the rundown:
August ended with an average temperature of 78.4 degrees. That made it 3.9 degrees above the 30-year average. It wasn't as hot as July, which averaged 79.8 degrees at BWI-Marshall. But when compared with the monthly averages, August saw a greater departure from the norm than July: 3.9 degrees, versus 3.3 degrees.
August was also the driest month of the summer. The airport recorded just 1.45 inch of rain in August. That was 2.29 inches below the 30-year norm.
As for the Summer of 2006, despite the moderate agricultural drought that developed in the season's closing weeks, the summer averaged out close to normal. That's because of all the torrential rain that fell at the end of June. We had 7.32 inches of rain in June, leaving a surplus of 3.89 inches to work from during the balance of the summer. July was dry, with just 1.86 inches of rain. That drained 1.99 inches from the surplus. August tapped 2.29 inches more and wiped out the June surplus entirely. In the end, the summer finished with a rain deficit of just 0.39 inch at BWI. Practically average in the end, despite all the rather extreme weather along the way.
Temperature-wise, the Summer of 2006 ended on the hot side. The average temperature was 77.1 degrees, or 2.8 degrees above the 30-year norm. That makes it the hottest summer since 1995, which averaged 78.7 degrees. The airport counted 37 days (June through August) with daily highs of 90 degrees or more.
September is a transitional month. The astronomical summer ends this year with the Autumnal Equinox, which occurs at 6 minutes after midnight on Sept. 23.
September is still very summery in Baltimore. But the weather does get much more pleasant. At BWI, the average high temperature slips during September from 82 degrees on the 1st, to 73 degrees on the 30th. The average daily lows drop from 61 degrees to 51 degrees.
It can still be very hot. The record maximums remain solidly in the 90s, with a few 100-plus daily records on the books. But there can be a real touch of fall. The record lows range from 67 degrees (on the 4th) to just 49 degrees (on the 28th).
Average rainfall in September is 3.98 inches. (It's never snowed in Baltimore in September - at least not since record-keeping began in 1871.) The wettest September was in 1934, when 12.41 inches fell. The driest was in 1884, when the city received a scant nine hundredths of an inch.