Weather in Indianapolis in January

The month to avoid. Of the twelve, January is the one to avoid. Highs sit at 1.3 °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 Indianapolis's year. September is the month that works, and the swing between the two is 62 points, which is a different holiday rather than a slightly better one.

Rain on 9 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 1.3 °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 18.5 °C and the coldest night fell to -27.7 °C, and the wettest single day dropped 45 mm — roughly 60% of the month's rain in one day.

January is moderately variable: 23 mm in the driest year against 212 mm in the wettest, around an average of 75 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 13.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 87%, which at 1.3 °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 Indianapolis's year — 9.6 hours of daylight against 15 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 — 35.6 °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 Indianapolis versus nearby

If Indianapolis is one option among several, the nearby comparison is worth making. Louisville is close enough to be a coin toss — 2.9 °C warmer, the same number of rain days. Fort Wayne is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: January is a compromise. September is 62 points better and is what Indianapolis 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 Indianapolis

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