Somo has some of the coldest winter nights among U.S. towns
July afternoons average 78°. A year here swings 75° from midwinter lows to midsummer highs. Summers stay cool: July afternoons here are cooler than in 96% of U.S. towns. The heating season runs October to April: each of those months averages under 50°.
A year in Somo at a glance
Each month’s typical high and low, and what it brings.
What stands out about Somo’s climate
Compared with towns across the U.S., with Somo’s place in Wisconsin beside it.
What a year in Somo feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 146 frost-free days a year
In half of years the last 32° night comes by May 10 and the first by October 4. Frost and day counts come from NOAA’s station at Rice Reservoir Tomahawk-2, WI, 13 miles from the town’s center, at about the same height.
The 2023 USDA map puts Somo’s center in zone 4a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −26°. 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 62 inches of snow a winter
Snow, measured at Spirit Falls, WI, falls mostly in January. Precipitation (rain plus melted snow) adds up to 33 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 105 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Somo
97% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Rice Reservoir Tomahawk-2, WI.
Living with Somo’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
146 frost-free days in zone 4a. The last frost comes by May 10 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 4.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 0.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Somo from natural hazards, river flooding is the largest share (51%); heat waves, cold waves, winter storms and ice storms together are 38%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Somo and its neighbors
Every town next door is within a degree of Somo in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Somo’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 |
|---|---|---|---|---|
| Somo, WI | 3° | 78° | 33" | 62" |
| Grand Rapids, MN | −2° | 79° | 28" | 60" |
| Beekmantown, NY | 9° | 80° | 35" | 80" |
| Littleton, NH | 6° | 80° | 40" | 68" |
| St. Johnsbury, VT | 5° | 79° | 41" | 87" |
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 Somo averaged 1.6° warmer than the 1900s. The biggest change is in December (+3.4°).
A bigger shift than in 64% 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 Somo compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Somo’s place among Wisconsin’s.
Somo weather by month
Highs, lows and precipitation from NOAA’s grid at Somo’s center; snow, wet days and snow on the ground from Spirit Falls, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 21° | 3° | 1.2" | 13.8" | 9 | 0° – 24° |
| February | 26° | 5° | 1.1" | 12.1" | 6 | 3° – 30° |
| March | 38° | 16° | 1.7" | 10.6" | 7 | 17° – 42° |
| April | 51° | 29° | 2.9" | 4.3" | 9 | 30° – 48° |
| May | 65° | 41° | 3.6" | 0.2" | 10 | 46° – 60° |
| June | 74° | 51° | 4.4" | 0.0" | 10 | 58° – 68° |
| July | 78° | 55° | 3.8" | 0.0" | 10 | 61° – 71° |
| August | 76° | 53° | 3.7" | 0.0" | 9 | 60° – 69° |
| September | 68° | 46° | 3.6" | 0.0" | 9 | 50° – 62° |
| October | 54° | 34° | 3.3" | 1.3" | 9 | 37° – 49° |
| November | 38° | 23° | 1.9" | 8.1" | 8 | 21° – 40° |
| December | 26° | 11° | 1.5" | 11.1" | 9 | 6° – 28° |
| Year | 51° | 31° | 32.7" | 61.5" | 105 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 3° to 30°. August is the most reliable, staying within 9°.
Where Somo’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 Somo’s center.
- Snow: Spirit Falls, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rice Reservoir Tomahawk-2, WI, 13 miles from the town’s center, at about the same height; 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 Somo’s climate
What is the weather like in Somo?
A typical July afternoon reaches 78°, a January night drops to 3°, and about 62 inches of snow falls in a normal winter. Colder January nights than all but 123 U.S. towns; cooler July afternoons than 96% of U.S. towns.
How cold does it get in Somo in winter?
January nights average 3°. About 177 nights a year reach 32° or below and 40 reach 0° or below. In the coldest January of the last 30 years the month averaged 0°.
How much snow does Somo get?
About 62 inches in a normal winter at Spirit Falls, WI, most of it in January.
How hot does it get in Somo?
July, with a typical high of 78° and a low of 55°. About 1 days a year reach 90° (Rice Reservoir Tomahawk-2, WI).
When is the first and last frost in Somo?
In half of years the last spring frost (32°) comes by May 10 and the first fall frost by October 4, about 146 frost-free days, at Rice Reservoir Tomahawk-2, WI.
What growing zone is Somo in?
Zone 4a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −26°.
What is the best time of year to visit Somo?
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 Somo getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 64% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Somo.
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.