Historical weather data, all-time temperature records, and monthly climate averages for Affton, MO. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Affton runs mild, with an average high of 65° and low of 39°—classic transitional spring weather. The date has seen some wild swings over 28 years, from a balmy 82° in 2010 down to a bitter 26° in 2002. There's about a 1-in-3 chance of rain today, but snow is essentially off the table.
Affton earns its Midwest stripes with a punishing 121-degree spread between its all-time extremes: a scorching 107° on June 28, 2012, and a brutal -14° on January 7, 2014. The wettest single day on record—7.23 inches on July 26, 2022—is a reminder that summer storms here mean business.
Summer is the main event in Affton, with highs peaking around 91° the third week of July and staying in the upper 80s through August. If you want to avoid the heat, mid-January is the coolest stretch, averaging just 39° for a high. Plan around rain in late June and early July, the wettest stretch of the year at nearly 1.5 inches per week.