Historical weather data, all-time temperature records, and monthly climate averages for Greendale, WI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Greendale sits right on the cusp of spring, with an average high of 48° and a low that still dips to freezing. The date has a wild range in the record books — 67° in 1981 was practically t-shirt weather, while just one year later in 1982, temperatures bottomed out at 15°. Rain is nearly a coin flip at 44%, but snow is off the table.
Greendale's weather has real teeth at both extremes — the thermometer has hit 102° in summer and plunged to -26° in winter, a brutal 128-degree swing over the years. The wettest single day on record dropped an extraordinary 8.76 inches in August 2025, and a February 1974 snowstorm buried the area under 13.6 inches in one shot.
Summer is the sweet spot, with highs peaking around 83-84° in mid-July and staying comfortable through August. If you're avoiding the cold, steer clear of January — the coolest week of the year averages just 27° for a high. Pack an umbrella for early June, historically the wettest stretch of the year at over an inch of precipitation per week.