What Does the Unusually Warm Start to the Summer Mean for the Coming Months?

There is no denying that the beginning of summer was a hot one. Temperatures across the country soared into triple digits and the heat was blamed for several deaths. In fact, the start of the entire year has been the warmest on record, 4.5 degrees F above average. While the heat, for most of the country, has subsided for the moment, parts of the nation could see rebounding temperatures as early as the weekend. With no definitive end in sight, what might be in store for the United States in the winter months, and next summer?

If you want to examine the aftermath of exceptionally warm summers, you don't have far to look. Last year was the second-hottest summer ever, trailing 1936 (one of the Dust Bowl years) by just a tenth of a degree. Last year's heat wasn't just a fluke, either. The two years prior to 2011- '09 and '10- both reached the top five, as did 2006.

However, the winters following these recent heat waves haven't been quite as consistent. You may recall that the 2009-10 winter was somewhat mild, yet the next winter, after another top-five summer, was exceptionally cold and wet. The reason for this may lie in one of climatology's greatest mysteries: El Niño. El Niño and its inverse, La Niña, wreak havoc on the world's temperatures and precipitation at rather irregular intervals. El Niño tends to cause warmer, drier spells in North America, while La Niña causes the opposite.¹ 

La Niña occurred over the 2010-11 winter, playing a role in the severe conditions we experienced then. El Niño affected 2009, however, and caused a somewhat warmer winter. What does the phenomenon have in store for us this time? Not much; the condition was back to neutral by April 2012 and remains that way. However, NOAA has forecasted probable El Niño conditions for the upcoming winter, which could mean another mild season.

It must be remembered that El Niño and La Niña don't provide perfect climate predictions- other factors also play a role in the weather. Last winter, the U.S. experienced La Niña again, yet had a fairly mild winter. However, based on recent trends and forecasts from NOAA, we can reasonably predict a mild winter and yet another hot summer in store for us in the next year.


¹El Niño has different effects on different parts of the United States; for example, the South (particularly the Southwest) is affected in nearly the opposite way than the Upper Midwest and Great Lakes States.