Weather in St. Louis in January

The month to avoid. Of the twelve, January is the one to avoid. Highs sit at 4.1 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

January ranks 12 of 12 — near the bottom of St. Louis's year. October is the month that works, and the swing between the two is 53 points, which is a different holiday rather than a slightly better one.

Rain on 7 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 4.1 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: 27 nights drop below freezing, so anything left outside stays frozen. Across the twenty years measured, the hottest January day reached 20.8 °C and the coldest night fell to -22.2 °C, and the wettest single day dropped 52 mm — roughly 83% of the month's rain in one day.

January is moderately variable: 13 mm in the driest year against 172 mm in the wettest, around an average of 63 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 10.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 82%, which at 4.1 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How January sits in the year

This is a turning point in the year — December and February sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in January

January sits at the dark end of St. Louis's year — 9.7 hours of daylight against 14.8 at midsummer, gaining 0.7 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

With no coast nearby, the year swings a fair way — 36.6 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in St. Louis versus nearby

If St. Louis is one option among several, the nearby comparison is worth making. Indianapolis is close enough to be a coin toss — 2.8 °C cooler, 2 days more rain. Kansas City is close enough to be a coin toss — within a degree on temperature, 2 days less rain.

So: January is a compromise. October is 53 points better and is what St. Louis is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in St. Louis

See all twelve months in St. Louis, or where else to go in January.