Historical weather data, all-time temperature records, and monthly climate averages for Watertown, WI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Watertown is a classic late-winter coin flip — historically, highs average just 51° with lows still dipping to freezing. The date has swung wildly over 133 years of records, from a balmy 78° in 1921 to a brutal 13° low in 1995. There's about a 1-in-3 chance of precipitation today, though snow is unlikely at just 3%.
Watertown plays for keeps on both ends of the thermometer — 133 years of data show a 137-degree swing between its all-time high of 104° in July 1901 and a bone-chilling -33° in February 1929. Summer storms can be savage too, with a single day in July 1982 dropping 6.65 inches of rain, and a January 1897 snowstorm burying the city under 19 inches.
Watertown earns its summers, with highs peaking around 84° in mid-July before the long slide back to a frigid 27° average in early January. June is the wettest stretch of the year, averaging over an inch of precipitation in a single week. If you're planning a visit, July and August offer the warmest and most reliably pleasant weather; spring and fall are mild but unpredictable.