User:Nje310/2009 Seattle heat wave

The 2009 Seattle heat wave was a heat wave which affected the Pacific Northwest region in Oregon and Washington west of the Cascade Mountains, and is well-known for setting many new heat records across the area, especially breaking the previous all-time record high temperature in Seattle by three Fahrenheit degrees (1.7 Celsius degrees). The heat wave was made worse by the fact that heat of this magnitude is rare in the Northwest; thus, air conditioners and other methods for cooling are not common in this region.

Weather
The temperatures soared to record highs in late July from Medford, Oregon to Seattle, Washington, and as far north as the Northwest Territories in Canada. The hottest weather occurred from July 26 to August 2, with the peak of the heat from July 28 to July 30. The high of 103 °F at Seattle-Tacoma International Airport on July 29 set the record for the hottest temperature ever in Seattle since records began in 1894, breaking the old record of 100 °F set on July 16, 1941 when the official weather station was located in downtown Seattle, and tied on July 20, 1994 at Seattle-Tacoma International Airport. Nighttime low temperatures were unusually high as well &mdash; in the upper 60s and lower 70s °F (about 21 °C). The morning of July 29, Seattle also set a new record warmest low temperature, 71 °F, breaking the old record of 69 °F set on September 2, 1974 and tied a day earlier on July 28, 2009.

The heat was not confined to Seattle. Portland International Airport in Oregon reached 106 °F on two consecutive days on July 28 and 29, nearly tying the all-time record there of 107 °F. Portland tied its warmest low temperature on record with a low of 74 °F on July 28.

The heat was part of a summer that was overall very warm in the Northwest. Seattle recorded its second warmest July on record with an average temperature of 69.45 °F, trailing only July 1941 (average temperature of 69.55 °F), and the third warmest month on record, trailing July 1941 and August 1967 (average temperature of 71.1 °F). The June 1 to July 31 time period was the warmest on record in Seattle with an average temperature of 66.7 °F, besting the previous warmest June/July period of 1958 (average temperature of 66.4 °F).

Fire Weather
The heat wave came during a year that was very dry in the Northwest as well, leading to enhanced wildfire threats across the region. From May 20 through August 2, Seattle only recorded 0.24 inches of precipitation, the lowest on record for this time period. The previous low for the same period was 0.62 inches in 1938. Normal precipitation during this time period is 2.92 inches.

Statistics
Seattle's daily temperatures during the 2009 heat wave:
 * July 26: High 89 °F, Low 61 °F
 * July 27: High 94 °F, Low 65 °F
 * July 28: High 97 °F, Low 69 °F
 * July 29: High 103 °F, Low 71 °F
 * July 30: High 96 °F, Low 62 °F
 * July 31: High 84 °F, Low 58 °F
 * August 1: High 90 °F, Low 57 °F
 * August 2: High 89 °F, Low 60 °F

Portland, Oregon's daily temperatures during the 2009 heat wave:
 * July 26: High 93 °F, Low 61 °F
 * July 27: High 103 °F, Low 68 °F
 * July 28: High 106 °F, Low 74 °F
 * July 29: High 106 °F, Low 71 °F
 * July 30: High 96 °F, Low 67 °F
 * July 31: High 94 °F, Low 62 °F
 * August 1: High 95 °F, Low 63 °F
 * August 2: High 94 °F, Low 65 °F