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Year-to-Date Temperature Trends

By Climate Central


  • Places that started the year with temperatures much below normal have rebounded, now with year-to-date temperatures close to normal, or even above normal.
  • 17 state capitals had one of their 5 hottest Septembers on record.
  • With El Niño in place, temperatures across the northern tier of the U.S. will likely be above normal this coming winter.

Summer seems to have lasted a little longer in much of the country this year, as several cities have had one of their 5 hottest Septembers on record. Heat has been the main theme in the West all year, but until recently, the East had not shown the same pattern.

This analysis looks at how the year-to-date temperature has evolved, when compared to normal, during the course of this year. Many cities that were much colder than normal for the first two months of the year, are now running near normal or even above normal for the year.

Nationally, when one coast is cool, the other is usually warm. But despite the heat along the East Coast in September, the West Coast did not turn cool. Temperatures in Seattle and Portland were near normal, but Los Angeles, Phoenix, Salt Lake City, and San Francisco were all hotter than normal. A sampling of state capitals reveals that 17 of the 50 capitals had one of their 5 hottest Septembers on record. Two of these (Cheyenne and Denver) had their hottest September on record.

Globally, 2015 is the hottest year on record so far – and it’s been running that way nearly all year. Nationally, we’re on pace to be one of the top 10 hottest years.

Power of El Niño

With the current strong El Niño in place, cold outbreaks will likely be reduced in the coming months, as El Niño tends to decrease the amount of cold air surging into the U.S. from Arctic regions. As a result, a repeat of last winter is not likely in the Northeast.

While cold spells in winter will continue, the extent and strength of the winter cold will likely decrease in the coming decades as the climate changes. The result will be fewer brutal winters, so what was seen in the Northeast last winter will become less common in the future.