Forest sits near the bottom of U.S. towns for winter warmth
High summer brings afternoon highs near 81°. By July afternoons alone, it runs cooler than 90% of U.S. towns. Decade by decade the climate has edged up, 1.2° above 1901–2000. Seedlings are safe outdoors from about May 12, with the first autumn frost due around September 29.
A year in Forest at a glance
Each month’s typical high and low, and what it brings.
What stands out about Forest’s climate
Compared with towns across the U.S., with Forest’s place in Wisconsin beside it.
What a year in Forest feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 138 frost-free days a year
In half of years the last 32° night comes by May 12 and the first by September 29. Frost and day counts come from NOAA’s station at Hillsboro 2sw, WI, 7 miles from the town’s center, 160 ft lower.
The 2023 USDA map puts Forest’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −19°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 41 inches of snow a winter
Snow, measured at Ontario 3e, WI, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 37 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 103 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Forest
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Hillsboro 2sw, WI.
Living with Forest’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
138 frost-free days in zone 5a. The last frost comes by May 12 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 29.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 8.0 miles of trails are waiting.
Parks & trails →Cold waves are 41% of the yearly building losses FEMA expects in Forest from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Forest and its neighbors
Hillsboro the hottest July afternoons (82°, 1° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Forest’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Forest, WI | 8° | 81° | 37" | 41" |
| Peru, NY | 9° | 80° | 35" | 50" |
| Elko New Market, MN | 7° | 82° | 34" | 41" |
| Colchester, VT | 10° | 81° | 38" | 50" |
| Algona, IA | 8° | 83° | 34" | 37" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Forest averaged 1.2° warmer than the 1900s. The biggest change is in December (+3.1°).
A smaller shift than in 60% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Forest compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Forest’s place among Wisconsin’s.
Forest weather by month
Highs, lows and precipitation from NOAA’s grid at Forest’s center; snow, wet days and snow on the ground from Ontario 3e, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 24° | 8° | 1.2" | 11.1" | 7 | 25 | 5° – 29° |
| February | 30° | 11° | 1.1" | 8.3" | 6 | 24 | 8° – 32° |
| March | 42° | 22° | 2.0" | 6.4" | 7 | 14 | 23° – 48° |
| April | 56° | 33° | 3.7" | 1.7" | 10 | 1 | 34° – 51° |
| May | 68° | 45° | 4.6" | 0.0" | 11 | 0 | 50° – 63° |
| June | 77° | 55° | 5.3" | 0.0" | 11 | 0 | 62° – 71° |
| July | 81° | 59° | 4.5" | 0.0" | 9 | 0 | 64° – 77° |
| August | 79° | 57° | 4.3" | 0.0" | 9 | 0 | 63° – 73° |
| September | 71° | 49° | 4.0" | 0.0" | 9 | 0 | 53° – 66° |
| October | 58° | 37° | 2.7" | 0.1" | 9 | 0 | 42° – 54° |
| November | 42° | 26° | 2.1" | 2.0" | 7 | 3 | 26° – 45° |
| December | 30° | 14° | 1.5" | 11.5" | 8 | 18 | 9° – 32° |
| Year | 55° | 35° | 37.0" | 41.1" | 103 | 86 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 23° to 48°. June is the most reliable, staying within 8°.
Where Forest’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Forest’s center.
- Snow: Ontario 3e, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Hillsboro 2sw, WI, 7 miles from the town’s center, 160 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Forest’s climate
What is the weather like in Forest?
A typical July afternoon reaches 81°, a January night drops to 8°, and about 41 inches of snow falls in a normal winter. Colder January nights than 96% of U.S. towns; cooler July afternoons than 90% of U.S. towns.
How cold does it get in Forest in winter?
January nights average 8°. About 181 nights a year reach 32° or below and 32 reach 0° or below. In the coldest January of the last 30 years the month averaged 5°.
How much snow does Forest get?
About 41 inches in a normal winter at Ontario 3e, WI, most of it in January and December, with snow on the ground about 86 days a year.
How hot does it get in Forest?
July, with a typical high of 81° and a low of 59°. About 2 days a year reach 90° (Hillsboro 2sw, WI).
When is the first and last frost in Forest?
In half of years the last spring frost (32°) comes by May 12 and the first fall frost by September 29, about 138 frost-free days, at Hillsboro 2sw, WI.
What growing zone is Forest in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −19°.
What is the best time of year to visit Forest?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Forest getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Forest.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.