St. Louis’ first freeze will be one of the city’s latest ever

After eight months of above-freezing temperatures, the first frost of the season is likely to arrive in St. Louis early Tuesday morning amid a fall marked by above-normal temperatures.

Temperatures are expected to drop into the upper 20s to lower 30s early Tuesday, which would tie for the second-most recent first freeze since 1874, according to National Weather Service data.

It’s almost a month late. The average first freeze is October 31.

The above average temperatures are at odds with recent trends.

“The late October to mid-November period has actually gotten a little bit cooler over the last 10 to 20 years, obviously not this year,” said Jayson Gosselin, a meteorologist with the National Weather Service in St. Louis. “We’ve had kind of a cool end of October, early to mid-November, more often than not the last few decades.”

Last time St. Louis felt the freezing temperatures on March 19. With a freeze Tuesday morning, there would be 252 days between freezes, 45 days longer than average and just eight days shy of the record, with data dating back to 1874.

Many outlying areas around St. Louis experienced freezing temperatures last month, Gosselin said, but the official St. Louis weather station in St. Louis Lambert International Airport remained above freezing.

This month, St. Louis temperatures have been 6.7 degrees above normal.

“It’s been pretty consistently hot,” Gosselin said. “For the most part, the last five weeks have been above average.”

Later in the week, keep an eye on the weather forecast for Wednesday and Thursday, especially for travelers heading north for a holiday.

“Looks like we’re going to get some rain around here,” Gosselin said. “Looks primarily overnight, Wednesday night into Thursday morning. There is still some uncertainty about the track and strength of the system, but right now there are some low chances for some snow to mix up toward Quincy and point north.”

For the coming winter, an outlook was issued this week by the National Weather Service’s Climate Prediction Center does not provide much clarity for St. Louis, giving the region an equal chance of above- or below-normal temperatures and precipitation in the months of December through February.

Gosselin said the outlook gave “no clear signal.”

If recent history is any guide, December could be warmer than average.

“We’re seeing that December, specifically that month, has warmed more than others,” Gosselin said. “It’s the month that sticks out.”

For snow lovers, a recent one Washington Post report illustrated the fall of snow in St. Louis.

St. Louis received 26.9% less snow on average from 1994-2016 (19 inches) than it did from 1964-93 (26 inches). Percentage-wise, the region had a greater decrease than most of the rest of the country.

A forecast from the Post, based on a mix of global weather models, predicts less snowfall in St. Louis this winter than even the meager recent average.