Photo: RRGreenough · CC BY-SA 4.0Tomah has some of the coldest winter nights among U.S. towns
In July the day’s top temperature is typically 81°. June is the wettest month, February the driest. Summers stay cool: July afternoons here are cooler than in 87% of U.S. towns. The heating season runs October to April: each of those months averages under 50°.
A year in Tomah at a glance
Each month’s typical high and low, and what it brings.
What stands out about Tomah’s climate
Compared with towns across the U.S., with Tomah’s place in Wisconsin beside it.
What a year in Tomah feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 144 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by October 1. Frost and day counts come from NOAA’s station at Sparta, WI, 16 miles from the town’s center, 310 ft lower.
The 2023 USDA map puts Tomah’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −20°. 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 48 inches of snow a winter
Snow, measured at Mather 3 Nw, WI, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 36 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 112 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Tomah
94% 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 Sparta, WI.
Living with Tomah’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
144 frost-free days in zone 5a. The last frost comes by May 9 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 1.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 1.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Tomah from natural hazards, river flooding is the largest share (50%); heat waves, cold waves, winter storms and ice storms together are 30%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Tomah and its neighbors
Every town next door is within a degree of Tomah in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Tomah’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 |
|---|---|---|---|---|
| Tomah, WI | 7° | 81° | 36" | 48" |
| Clear Lake, IA | 7° | 82° | 36" | 44" |
| Plattsburgh, NY | 9° | 81° | 35" | 50" |
| Forest Lake, MN | 5° | 82° | 33" | 52" |
| Colchester, VT | 10° | 81° | 38" | 50" |
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 Tomah averaged 1.4° warmer than the 1900s. The biggest change is in December (+3.3°).
A bigger shift than in 52% 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 Tomah compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Tomah’s place among Wisconsin’s.
Tomah weather by month
Highs, lows and precipitation from NOAA’s grid at Tomah’s center; snow, wet days and snow on the ground from Mather 3 Nw, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 24° | 7° | 1.2" | 11.3" | 7 | 24 | 5° – 29° |
| February | 30° | 10° | 1.1" | 10.3" | 6 | 24 | 7° – 32° |
| March | 42° | 21° | 1.9" | 7.4" | 8 | 14 | 23° – 48° |
| April | 56° | 33° | 3.6" | 3.5" | 12 | 2 | 33° – 51° |
| May | 68° | 45° | 4.4" | 0.0" | 12 | 0 | 51° – 63° |
| June | 77° | 55° | 5.0" | 0.0" | 11 | 0 | 62° – 71° |
| July | 81° | 59° | 4.3" | 0.0" | 10 | 0 | 64° – 77° |
| August | 79° | 57° | 4.4" | 0.0" | 10 | 0 | 63° – 73° |
| September | 71° | 48° | 3.8" | 0.0" | 10 | 0 | 53° – 66° |
| October | 58° | 37° | 2.7" | 0.5" | 9 | 0 | 42° – 53° |
| November | 42° | 25° | 1.9" | 2.9" | 8 | 3 | 25° – 45° |
| December | 30° | 14° | 1.5" | 12.0" | 8 | 18 | 8° – 32° |
| Year | 55° | 34° | 35.6" | 47.9" | 112 | 85 |
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 Tomah’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 Tomah’s center.
- Snow: Mather 3 Nw, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Sparta, WI, 16 miles from the town’s center, 310 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 Tomah’s climate
What is the weather like in Tomah?
A typical July afternoon reaches 81°, a January night drops to 7°, and about 48 inches of snow falls in a normal winter. Colder January nights than 97% of U.S. towns; cooler July afternoons than 87% of U.S. towns.
How cold does it get in Tomah in winter?
January nights average 7°. About 165 nights a year reach 32° or below and 25 reach 0° or below. In the coldest January of the last 30 years the month averaged 5°.
How much snow does Tomah get?
About 48 inches in a normal winter at Mather 3 Nw, WI, most of it in January and December, with snow on the ground about 85 days a year.
How hot does it get in Tomah?
July, with a typical high of 81° and a low of 59°. About 11 days a year reach 90° (Sparta, WI).
When is the first and last frost in Tomah?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by October 1, about 144 frost-free days, at Sparta, WI.
What growing zone is Tomah in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −20°.
What is the best time of year to visit Tomah?
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 Tomah getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 52% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Tomah.
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.