Hardly any U.S. towns see harsher January nights than Seneca
The warmest part of a July day comes in at 81° on average. Winter and summer sit 74° apart. In July, afternoons here are cooler than in 90% of U.S. towns. The outdoor season runs from May to September, with highs of 67–81°.
A year in Seneca at a glance
Each month’s typical high and low, and what it brings.
What stands out about Seneca’s climate
Compared with towns across the U.S., with Seneca’s place in Wisconsin beside it.
What a year in Seneca feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 141 frost-free days a year
In half of years the last 32° night comes by May 13 and the first by September 30. Frost and day counts come from NOAA’s station at Stockbridge-munsee Rsvn, WI, 4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Seneca’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 Shawano 2ssw, WI, is heaviest from January through February, about 11 inches a month. 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 118 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Seneca
97% 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 Stockbridge-munsee Rsvn, WI.
Living with Seneca’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
141 frost-free days in zone 5a. The last frost comes by May 13 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 30.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 8.5 miles of trails are waiting.
Parks & trails →Cold waves are 45% of the yearly building losses FEMA expects in Seneca from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Seneca and its neighbors
Every town next door is within a degree of Seneca in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Seneca’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 |
|---|---|---|---|---|
| Seneca, WI | 7° | 81° | 33" | 48" |
| Medina, MN | 6° | 82° | 32" | 45" |
| Peru, NY | 9° | 80° | 35" | 50" |
| Clear Lake, IA | 7° | 82° | 36" | 44" |
| 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 Seneca averaged 1.9° warmer than the 1900s. The biggest change is in December (+3.6°).
A bigger shift than in 85% 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 Seneca compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Seneca’s place among Wisconsin’s.
Seneca weather by month
Highs, lows and precipitation from NOAA’s grid at Seneca’s center; snow, wet days and snow on the ground from Shawano 2ssw, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 24° | 7° | 1.2" | 11.8" | 10 | 27 | 4° – 27° |
| February | 29° | 9° | 1.1" | 10.8" | 7 | 27 | 7° – 30° |
| March | 41° | 20° | 1.8" | 7.4" | 8 | 18 | 20° – 45° |
| April | 54° | 31° | 3.1" | 4.3" | 10 | 3 | 33° – 50° |
| May | 67° | 43° | 3.6" | 0.0" | 12 | 0 | 48° – 62° |
| June | 76° | 53° | 4.5" | 0.0" | 12 | 0 | 61° – 70° |
| July | 81° | 57° | 3.8" | 0.0" | 11 | 0 | 63° – 74° |
| August | 78° | 56° | 3.6" | 0.0" | 10 | 0 | 62° – 71° |
| September | 71° | 48° | 3.5" | 0.0" | 10 | 0 | 53° – 65° |
| October | 57° | 36° | 2.9" | 0.3" | 10 | 0 | 42° – 52° |
| November | 42° | 25° | 1.9" | 3.5" | 8 | 4 | 24° – 42° |
| December | 29° | 14° | 1.5" | 9.8" | 9 | 20 | 10° – 32° |
| Year | 54° | 33° | 32.5" | 47.9" | 118 | 100 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 20° to 45°. June is the most reliable, staying within 8°.
Where Seneca’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 Seneca’s center.
- Snow: Shawano 2ssw, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Stockbridge-munsee Rsvn, WI, 4 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 Seneca’s climate
What is the weather like in Seneca?
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 90% of U.S. towns.
How cold does it get in Seneca in winter?
January nights average 7°. About 178 nights a year reach 32° or below and 31 reach 0° or below. In the coldest January of the last 30 years the month averaged 4°.
How much snow does Seneca get?
About 48 inches in a normal winter at Shawano 2ssw, WI, heaviest from January through February, about 11 inches a month, with snow on the ground about 100 days a year.
How hot does it get in Seneca?
July, with a typical high of 81° and a low of 57°. About 2 days a year reach 90° (Stockbridge-munsee Rsvn, WI).
When is the first and last frost in Seneca?
In half of years the last spring frost (32°) comes by May 13 and the first fall frost by September 30, about 141 frost-free days, at Stockbridge-munsee Rsvn, WI.
What growing zone is Seneca 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 Seneca?
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 Seneca getting warmer?
Yes: 1991–2020 averaged 1.9° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 85% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Seneca.
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.