Historical weather data, all-time temperature records, and monthly climate averages for Hartford, WI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Hartford sits in that classic spring no-man's-land — the average high is only 49° with a low of 29°, so frost is still on the table. The date's history spans a wild 66-degree range, from a balmy 76° in 1988 down to a teeth-chattering 10° in 1982. Snow is nearly off the board at just 1% odds, but don't put the jacket away yet.
Hartford plays hardball with its extremes — 133 years of data reveal a 140-degree swing between its all-time high of 105° (July 31, 1999) and its bone-crushing low of -35° (January 11, 1979). A single September day in 1986 dumped 5.2 inches of rain, and an early November storm in 1896 buried the area under 16 inches of snow before most people had even thought about winter.
Summer is Hartford's headliner, with late July averaging a comfortable 83° high and June bringing the year's heaviest rainfall at around an inch per week. If you're cold-averse, avoid January through February, when highs barely crack the mid-to-upper 20s. Spring and fall offer a brief but pleasant shoulder season in the 40s–60s before the extremes take over.