Weather in Chicago in March

The month to avoid. Of the twelve, March is the one to avoid. Highs sit at 4.9 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

March ranks 9 of 12 in Chicago: past the worst of the year but short of September, which is the month to book if the dates are open.

Rain on 9 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 4.9 °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: 18 nights fall below freezing; the day barely swings — 5.7 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest March day reached 21 °C and the coldest night fell to -17.3 °C, and the wettest single day dropped 39 mm — roughly 63% of the month's rain in one day.

March is moderately variable: 19 mm in the driest year against 135 mm in the wettest, around an average of 62 mm. Roughly two Marchs in three land near that average, and the third does something else entirely.

Wind sits around 16.4 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 82%, which at 4.9 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How March sits in the year

The month is on the way up: 4.6 °C warmer than February, and April adds another 5.3 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in March

11.9 hours of daylight, gaining 1.4 hours across the month. That is between Chicago's extremes of 15.2 and 9.2 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 30.2 °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.

March in Chicago versus nearby

If Chicago is one option among several, the nearby comparison is worth making. Milwaukee is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Grand Rapids is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: March is a compromise. September is 51 points better and is what Chicago 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 Chicago

See all twelve months in Chicago, or where else to go in March.