Historical weather data, all-time temperature records, and monthly climate averages for Brookfield, WI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Brookfield sits squarely in the unpredictable shoulder season — expect a high near 49° and a low around 33°, with a 40% chance of precipitation. The date's range tells the whole story: it's hit 73° as recently as 2010, but bottomed out at 19° back in 1979.
Brookfield knows extremes. The thermometer has swung from a brutal -26° in January 1985 all the way up to 102° in June 1953 — a 128-degree spread that captures the full drama of a continental Wisconsin climate. On the wet side, a single August day in 2025 dumped an incredible 8.76 inches of rain.
Summer is the clear sweet spot, with highs peaking around 83–84° in mid-July and comfortable warmth stretching through August. Winters are legitimately cold — the coolest week of the year averages a high of just 27° in mid-January. If you're planning around rain, sidestep early June, which is Brookfield's wettest stretch of the year.