Wednesday, July 28, 2010

Summer of Simmer: Party Like It's 1999

Midnight Update: Today's high is confirmed by the midnight report. Assuming the next 3 days go as forecast, July will end up with an average of 82.9°, the 3rd hottest in history. August can then average 0.75° below average or warmer and this will be the hottest summer in Washington's 140 years of temperature history. Normal for August is 77.4°. (That's right, August can average nearly 6° cooler than this month, and it will still be a record-breaking summer!)

9 PM Update: There was apparently a high of 93° after 5:00, as has happened several times recently.

Original post:
After 2 consecutive days below 90°, Washington's preliminary high temperature today was 92°. Combined with a morning low of 75°, the day was 5° above the long-term average, and the month-to-date July average is now a wannabe record of 83.3°.

Another +5° or so are likely tomorrow, but a cooling trend going into the weekend could produce a below-average day on Saturday for the first time since July 3. Depending on how cool it can actually get Saturday morning, the monthly average will be in tight contention with 1999 for second place on the July temperature hit parade. The current forecast is for 63°, which would equal the low for this month. The last time the temperature was below 72° was July 4.

Regardless of the final standings for July, the combination with the record warm June is almost a mortal lock to be the hottest June-July by far. The 2-month average to date is a hefty 1.4° above the current record in 1994 and behind only July-August 1980 as the second hottest of any 2 consecutive months in Washington. All of the top 9 previous hottest pairs of consecutive months have been July-August, rather than June-July.

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