Historical weather data, all-time temperature records, and monthly climate averages for Saint Peters, MO. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Saint Peters sits right in that shoulder-season sweet spot — expect a high around 62° and a low near 40°, with about a 1-in-3 chance of rain. The date has seen wild swings over 130 years of records, from a scorching 89° in 1954 down to a bitter 17° in 1920.
Saint Peters doesn't mess around at the extremes — the all-time high of 115° on July 14, 1954 ranks among the most punishing days ever recorded in the region, while the -25° low from January 1894 shows winters here have real teeth. A single storm on July 26, 2022 dumped 9.2 inches of rain, and March 1912 buried the area under a foot of snow in one day.
Summer is the main event, with average highs hitting 90° in mid-July and staying in the upper 80s through August. If you're trying to avoid the heat, aim for January through February when highs hover around 40-44°. Mid-May is the wettest stretch of the year, so pack accordingly if you're visiting in the spring.