Connecticut experienced the warmest May in 110 years of record-keeping in the Hartford area.
The average monthly temperature was 66.0 degrees. That number is calculated by averaging the high and low temperatures for all 31 days of the month.
It was only a few months ago that the coldest February, and coldest month, was logged at the Hartford area climate site, which currently uses the weather station at Bradley International.
February 2015 came in with an average temperature of only 16.1 degrees.
So, what’s behind these recent extremes? It’s not clear-cut, but there are some possible explanations.
This spring was very dry across the region. In fact, Islip, New York, Kennedy Airport, New York and Worcester, Massachusetts experienced Mays that ranked the driest on record.
“Without water at the surface, all of the sun’s energy, the solar radiation, goes to warming up the soil (the ground) and the air just above it, rather than going into evaporating water,” according to Dr. Michael Rawlins, manager of the Climate System Research Center at UMass Amherst.
As for the record cold in February, another theory exists. Rawlins says some climate scientists are investigating the idea that a rapidly warming Arctic could be contributing to a weaker jet stream, leading to bigger dips in the atmospheric flow during the winter.
“One wonders, are there any links between warming in the Arctic and what’s happened over our winter,” Rawlins says.
The cold pattern back in February, and the warmth of the last several weeks, certainly had persistence. During May 2015 in the Hartford area, not one daily record high temperature was set. Yet, most of the days were above average. That’s how the record warmest May was achieved.
Rawlins notes “it seems like these patterns are staying stuck more.” Though it may make sense at first glance, it’s a controversial area of research and hypotheses continue to be tested.
As for a link between the warmest May in history and the upcoming summer, Rawlins isn’t aware of a strong correlation between a warm May and a warm summer. It’s important to note that seasonal outlooks are a different beast that the typical seven-day forecast.