Washington Summer Heat Record Clinched By Huge Margin

Midnight Update: It's official; the daily high/low of 96/71 goes into the record books to close out the Summer of Simmer 2010, subject to final quality control by the National Climatic Data Center.

5:25 PM Update: The final high temperature of meteorological summer comes in at 96°, confirming the new record. Updated charts to follow shortly.

5 PM Update: The hourly temperature has returned back to 94°, so the high of 95° is likely to hold, unless there was a higher reading between hours.

4 PM Update: The temperature of 95° at 4 pm clinches the higher summer average of 81.3°, barring an almost physically impossible breakdown in the low by midnight. This smashes the old record for hottest summer of 80.0° in 1980 by an unprecedented margin. The current monthly average also rises, to 80.1°, tying for the 9th hottest August.

3 PM Update: The temperature is 94° for the second consecutive hour.

Original post:
As of 2 pm today, the Washington high/low temperatures so far of 94/71 have broken the hottest average summer temperature record by an unprecedented margin of at least 1.2°. One more degree increase on the high, which is quite likely, would raise that to 1.3°. Normally, even individual monthly average temperature records are broken by only a tenth of a degree, so breaking the 3-month record by 12 or more times that amount is even more remarkable. This is the 52nd day of the summer with a temperature of 90° or higher and the 57th of the year.

Some of the records set this summer:

• Hottest summer
• Hottest 3 consecutive months
• Second hottest of any 2 consecutive months
  
• Hottest individual month (tied)
  
• Hottest June
  
• Hottest July (tied)
• First time any 3 months in the same year averaged 80° or higher
• First time summer average daily high exceeded 90°
• 5 individual daily highs