January in CT has been unusually warm. How does it compare to a 'normal' winter?

Connecticut's January weather forecast consists of above-normal temperatures and few signs of a snowstorm, a WFSB meteorologist says.

Photo of Abby Weiss

After experiencing one of the top-10 warmest years on record in 2022, Connecticut is starting the New Year with an unusually mild winter.

The first week of January 2023 was the state's eighth warmest in its recorded history, Mark Dixon, chief meteorologist at WFSB Channel 3, said.

Since Dec. 28, temperatures have stayed above average following a cold snap on Christmas weekend. Last week, parts of Connecticut reached 50 degrees.

"This is premature to say, but let's say the month ended right now; It would be the warmest January on record," Dixon said.

What's in store for the rest of January?

Monday marked the beginning of what is normally the coldest part of the year for Connecticut. The three-week period, which lasts until Jan. 30, has an average maximum temperature of 35 degrees.

But Dixon said those brisk weather conditions won't likely return to the Nutmeg State until at least the end of the month. Temperatures in New England are expected to remain above normal for the next eight to 14 days, according to The Climate Prediction Center

"The theme continues," Dixon said. "There are no real major shots of cold air coming our way, at least anytime in the near term."

Dixon also anticipates that the next major snowfall won’t occur until February.

"For people who are winter snow lovers, we may need to hold onto hope for February," he said.

On Friday, wind from the south is expected to bring 50-degree temperatures before colder air moves towards the state Friday night into Saturday. Spotty rain may turn into snowfall, which is unlikely to accumulate, Dixon said.

Sunday is projected to drop down to the upper 30s. Temperatures will then rise back up to the early 40s by Monday, he said.

"It’s chillier air, but not to the point where it’s normal for this time of year," Dixon said. "We’re still running above average."

How warm was December?

The unusually warm conditions match the National Oceanic Atmospheric Association’s predictions for winter in Connecticut, which anticipated La Niña conditions would bring higher-than-average temperatures to the Atlantic region for its third consecutive winter.

"We had that shot of cold air briefly toward the end of the year for Christmas," Dixon said. "And then it trended milder and we've been mild ever since."

Apart from that arctic blast, conditions in December were slightly milder and wetter than normal, with the average temperature for the month rising 1.4 degrees above normal, Dixon said.

The NOAA outlook also projected equal chances of more or less snow than usual. 

As of Jan. 10, Hartford’s snowfall deficit has accumulated to nine inches below the average for the winter season, Dixon said. In December, the deficit reached nearly four inches.

What is causing the mild conditions?

Besides La Niña, Dixon attributes the warm start to the 2022-23 winter season to a confluence of factors.

The jet stream over the Pacific Ocean, which is currently inundating California with rain, carries mild air from the West to the East Coasts in a process called zonal flow.  

The polar vortex in the Arctic tends to weaken in the winter and send shots of cold air to the eastern U.S., interrupting the warm flow from the West. But right now, the polar vortex is staying put, Dixon said.

“As long as the polar vortex remains more stable and stays to the north, that allows the west-to-east zonal flow to continue,” Dixon said.

Sea surface temperatures are also warmer than average, and the mild air pulled from the ocean deters rain from turning into snow, Dixon said. On Jan. 11, the coastal temperature in Bridgeport was 43 degrees, a few degrees above the January average.

What exactly does 'normal' mean? 

Meteorologists calculate average temperatures based on data from the most recent 30-year period and reset the numbers every decade, Dixon said.  NOAA updated the "normal" temperatures in 2020 based on data from 1991 to 2020. 

The NOAA normals increased in Connecticut and throughout most of the country. The most recent 30-year span, 1991 to 2020, was also the warmest on record for the U.S., according to NOAA.

For most of the U.S., winter is the fastest warming season, according to Climate Central. Climate change is leading to fewer cold days and is raising minimum temperatures.

In Connecticut, the average annual temperature rose from 50.6 to 51 degrees, and the winter average increased from 29. 1 to 29.7 degrees. Precipitation and snow levels also rose in Connecticut from 1991 to 2020 compared to the 1981 to 2010 time period, according to NOAA calculations.

While storms in Connecticut are increasingly carrying more precipitation, they are also becoming less frequent and more damaging, according to the CT Department of Energy and Environmental Protection. Warming temperatures also mean the snow will stick for a shorter amount of time.

The next set of "normals" will be released in 2030, Dixon said.