With meteorological summer now under way, we hate to bring back bad memories of this past winter. But I’m sure folks across the Northeast, Mid-Atlantic and Midwest remember cold temperatures dominating between the months of January and March. Even April featured some chilly days. So it might come as a complete surprise for those in the Eastern US that January through April 2015 was the warmest such period ever recorded on Earth!
The key phrase in the sentence above is “on Earth”. Obviously warm is not a word we would use to describe the first four months of 2015 across eastern North America. However, much of the planet measured temperatures well above average during this time period. This was highlighted especially over Western North America, and Northern Europe and Asia, where records were broken and temperature anomalies of 3 to 5°C (about 5 to 9°F) were common (see map below for global temperature departures from Jan-Apr 2015). Overall, the average global temperature was about 1.5°F above normal.
Global Temperature Departures from Jan-Apr 2015. Source: National Centers for Environmental Information
Of the locations that experienced below normal temperatures during the first four months of 2015, most departures were relatively modest. Average temperature anomalies across India, Southeast Asia and Northern Australia were generally within 1°C (2°F) of the norm. It is pretty evident from the map above that the only region that featured significant negative anomalies was the eastern half of North America, where temperatures departures were -1.5 to -3°C (-3 to -6°F) along the East Coast, and -1 to -2°C (-2 to -4°F) in the Midwest.
It is interesting to note that this is very similar to what happened during the first four months of 2014. Going forward, it will be fascinating to see if 2016 will be the third year in a row. While it might be fun to speculate, it is still a little too early to be making any bold predictions about the upcoming winter.
