Hartland, WI climate
Hartland has cold, snowy winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 12°, and about 40 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Hartland feels like
Winter
Spring
Summer
Fall
Hartland weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 28° | 12° | 1.6" | 11.1" | 11 | 22 | 10° – 32° |
| February | 31° | 15° | 1.5" | 9.8" | 10 | 19 | 11° – 35° |
| March | 43° | 24° | 2.0" | 4.8" | 10 | 8 | 26° – 48° |
| April | 56° | 35° | 3.7" | 2.0" | 12 | 1 | 36° – 51° |
| May | 68° | 46° | 4.0" | 0.2" | 13 | 0 | 51° – 63° |
| June | 78° | 56° | 4.7" | 0 | 12 | 0 | 63° – 72° |
| July | 82° | 60° | 3.9" | 0 | 10 | 0 | 66° – 78° |
| August | 80° | 58° | 3.9" | 0 | 10 | 0 | 64° – 75° |
| September | 73° | 51° | 3.3" | 0 | 10 | 0 | 56° – 67° |
| October | 60° | 39° | 2.9" | 0.1" | 11 | 0 | 45° – 56° |
| November | 45° | 29° | 2.2" | 1.4" | 10 | 2 | 27° – 46° |
| December | 33° | 18° | 1.8" | 10.2" | 11 | 13 | 13° – 36° |
| Year | 56° | 37° | 35.5" | 39.6" | 129 | 64 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Hartland
Hartland gets 36 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 129 days a year. Snow covers the ground about 64 days of the year.
About 164 frost-free days a year
In half of years the last 32° night comes by April 30 and the first one by October 12. That leaves about 164 frost-free days for gardens, shorter than 67% of U.S. towns.
Heating and cooling a home in Hartland
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Hartland, 92% of that work is heating and 8% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Hartland and its neighbors
Hartland borders 4 towns with climate data. January nights across them vary by 0.5°. Merton has the coldest January nights (12°) and Delafield the hottest July afternoons (82°). Hartland’s January low is 12° and its July high 82°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Hartland compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Hartland averaged 1.3° warmer than the 1900s. The biggest change is in December (+3.0°). The shift is larger than in 57% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Hartland’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 11° to 35°. June is the most reliable, staying within 9°.
Common questions about Hartland’s climate
What is the coldest month in Hartland?
January, with a typical high of 28° and a low of 12°.
What is the hottest month in Hartland?
July, with a typical high of 82° and a low of 60°. About 7 days a year reach 90°.
How much snow does Hartland get?
About 40 inches in a normal winter, most of it in January.
When is the first frost in Hartland?
In half of years the first 32° night comes by October 12, and the last spring frost by April 30.
What is the rainiest month in Hartland?
June, with 4.7 inches of rain and melted snow. The year totals 36 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Hartland itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Oconomowoc WWTP, WI (8 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.