Posted by Jeff Masters of Weather Underground:

The Great Russian Heat Wave of 2010 continues
One of the most remarkable weather events of my lifetime is unfolding this summer in Russia, where an unprecedented heat wave has brought another day of 102F heat to the nation's capital. At 3:30 pm local time today, the mercury hit 39C (102.2F) at Moscow's Domodedovo Airport. Moscow had never recorded a temperature exceeding 100F prior to this year, and today marks the second time the city has beaten the 100F mark. The first time was on July 29, when the Moscow observatory recorded 100.8C and Baltschug, another official downtown Moscow weather site, hit an astonishing 102.2F (39.0C). Prior to this year, the hottest temperature in Moscow's history was 37.2C (99F), set in August 1920. The Moscow Observatory has now matched or exceeded this 1920 all-time record four times in the past eleven days. The 2010 average July temperature in Moscow was 7.8C (14F) above normal, smashing the previous record for hottest July, set in 1938 (5.3C above normal.) July 2010 also set the record for most July days in excess of 30C--twenty-two. The previous record was 13 such days, set in July 1972. The past 24 days in a row have exceeded 30C in Moscow, and there is no relief in sight--the latest forecast for Moscow calls for high temperatures near 100F (37.8C) for the next seven days. It is stunning to me that the country whose famous winters stopped the armies of Napoleon and Hitler is experiencing day after day of heat near 100F, with no end in sight.

The extreme heat has led to the worst drought conditions in European Russia in a half-century, prompting the Russian government to suspend wheat exports. The drought has caused extreme fire danger over most of European Russia (Figure 3), and fires in Russia have killed at least 50 people in the past week and leveled thousands of homes. The fires are the worst since 1972, when massive forest and peat bog fires burned an area of 100,000 square km and killed at 104 people in the Moscow region alone. Smoke from the current fires spans a region over 3,000 km (1,860 miles) from east to west, approximately the distance from San Francisco to Chicago. Dozens of flights were canceled at Moscow's airports today, thanks to visibilities of 300 meters in smoke. Also of concern is fires that have hit the Bryansk region of western Russia, which suffered radioactive contamination from the Chernobyl nuclear disaster in nearby Ukraine. There are fears that fires may burn through the contaminated area, releasing harmful radiation into the atmosphere.