Detroit just completed the warmest spring in recorded history, according to the National Weather Service Forecast Office for Detroit and Pontiac. The average temperature from March 1 through May 31 was 55.2 degrees F, more than two degrees warmer than the previous record warm spring in 2010 and at least five degrees warmer than normal. The record includes the warmest March in Detroit's history, which the NWS Forecast Office called "the most unusual climate event to ever be recorded in Southeast Michigan" as well as record high temperatures for several days in May, including 94 degrees F on Memorial Day, breaking the previous record by two degrees.
Detroit was not alone in shattering records for the season. Flint and Saginaw also had the warmest springs in their histories. Like Detroit, Flint also exceeded the previous record from 1922 by more than two degrees, averaging 53.3 degrees F. In comparison, Saginaw merely edged out the previous record from 1978 by three-tenths of a degree with a mark of 52.4 degrees F.
The stretch of warm weather has lasted for more than a year in the area. Detroit has had above normal temperatures for thirteen consecutive months extending back to May 2011, including July 2011, the hottest month in the city's history. Flint has been warmer than normal even longer--fourteen consecutive months extending back to April 2011.
Based on the ending of La Nina in the eastern Pacific and the return to neutral conditions, the NWS Forecast Office predicts that the above normal temperatures will persist through July, for fifteen consecutive months of warmer than average weather. Precipitation is expected to be near normal during the next two months. The warm streak should break in August, when normal to slightly below normal temperatures should return. Precipitation should also increase that month and rainfall totals for the season should be in the normal range.
Record warmth has also been the experience of the rest of the United States, according to NOAA. The first four months of 2012 have been the warmest first four months of any year for the contiguous United States, with an average temperature of 45.4 degrees F, 5.4 degrees F above the long-term average. Twenty-six states, all east of the Rockies, recorded their highest averages for the four-month period, and an additional 17 states had temperatures for the period among their ten warmest.
In addition, the twelve consecutive months ending in April 2012 were the warmest in U.S. history. The twelve-month running average temperature for the contiguous U.S. was 55.7 degrees F, which is 2.8 degrees F above the Twentieth Century average. These months included the second hottest summer, fourth warmest winter, and warmest March ever recorded for the contiguous United States. Twenty-two states set records for highest average temperatures during the 12-month period, and an additional nineteen states experienced temperatures among the ten highest in their histories.
The rest of the planet can boast even more records. April 2012 was the warmest April on record for the Northern Hemisphere. Also, global average temperatures have been above the normal for the Twentieth Century normal every month from February 1985 until April 2012, with no reason to expect that May's readings will break the streak.
Stay cool, everybody.