ST. LOUIS – Over the last three years, we entered fall with the same La Niña pattern. It has meant some dry time for us, and a delay in the onset of the deeper fall chill.
But that pattern is now changing to an El Niño flavor, and we have already seen what that has meant to our weather. It’s been a more active pattern through the summer.
While the start of September has been mostly uneventful, fall is a transition season, and sometimes, it proves to be a second severe weather season.
Here’s what to watch for as St. Louis turns the page to fall this weekend:
September
September has started pretty quiet and mostly warm. In fact, September is never as cool as you think it should be. The first couple of weeks of the month have felt more like summer. We’ve had a nice stretch of great temps, but as we enter the second half of the month, we see more warm air building.
Overall, this September is shaping up like most other Septembers.
Last year, our September had some heat in the middle, and a cool stretch at the end, which averaged the temps to near normal for the month. This year, warm air is setting up again.
September 2022 was a dry one, around an inch short of normal precipitation levels. This September, our slow start to rain may keep us below normal once again.
October
October is a fun month to be outside. The heat of the summer is behind us, and there are some cool and crisp days and nights.
A couple of key benchmarks to watch for this month: The first frost and the first freeze historically come late. We normally get into the frost time from the middle to the end of the October, with the first freeze happening on average around Halloween.
This October, it’s possible we don’t get into the 30s for lows until late. We will wait until November for the first freeze.
This month is shaping up to start mainly dry, but in the middle of the month, there is a pattern shift that will bring in more active weather in the second half. That means more rain and storm opportunities. We’ve had snow on Halloween before, but this October, we probably won’t see any snow.
October 2022 had some warm days in the first half, then a big temperature drop middle of the month with the frost and freeze. Current projections show a mild month with some 30s, but freeze might hold off until November.
Last year, October was pretty dry with one big rainfall late in the month. This year could be pretty similar: Dry to start, but more rain and storm chances late.
November
November can be a crazy month with a mix of mild days and snow days. For the past few years, we’ve had snowflakes in November. This year, likely no exception.
The month will start very active with rain chances that may eventually lead to our first freeze within the first couple of weeks. That middle of the month chill will last about a week before temps go back above normal.
We will get some bonus days in November. The rest of the month, temperatures will stay above normal with smaller precipitation chances.
November 2022 was mild at the start before a gradual chill at the end of the month. This year is similar, with our first freeze expected within the first two weeks.
Last year, we had five days of recorded snow in November. It wouldn’t be surprising to see some snowflakes in the middle to late stages of the month.
This November, while there is the chance of a few flakes, snow will likely not be as prominent as the last few years.