Weather in St. Louis in June

A good month. June works. It is not the peak, but nothing about it fights you. Highs average 28.9 °C, lows 18.3 °C, and rain falls on 13 days — nothing in the month is working against you.

June ranks 5 of 12 in St. Louis: past the worst of the year but short of October, which is the month to book if the dates are open.

Rain on 13 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 28.9 °C days and 18.3 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 12 days top 30 °C — hot spells arrive, but they break. Across the twenty years measured, the hottest June day reached 42.5 °C and the coldest night fell to 7 °C, and the wettest single day dropped 51 mm — roughly 48% of the month's rain in one day.

June is moderately variable: 27 mm in the driest year against 231 mm in the wettest, around an average of 107 mm. Roughly two Junes in three land near that average, and the third does something else entirely.

Wind is light at 6.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How June sits in the year

The month is on the way up: 4.8 °C warmer than May, and July adds another 2.3 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short.

Daylight in June

June is at or near the longest days of St. Louis's year: 14.8 hours of daylight, holding steady all month. Evenings are the real gain — dinner outdoors still happens in full light.

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

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

June 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 — 2.2 °C cooler, 1 day more rain. Kansas City is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: June works, with October the better month by 15 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in St. Louis

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