Hardly any U.S. towns see harsher January nights than Trenton
In July the day’s top temperature is typically 81°. Summers stay cool: July afternoons here are cooler than in 86% of U.S. towns. The latest 30-year average runs 1.1° warmer than 1901–2000’s, with December up the most. The outdoor season runs from May to September, with highs of 68–81°.
A year in Trenton at a glance
Each month’s typical high and low, and what it brings.
What stands out about Trenton’s climate
Compared with towns across the U.S., with Trenton’s place in Wisconsin beside it.
What a year in Trenton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 173 frost-free days a year
In half of years the last 32° night comes by April 23 and the first by October 14. Frost and day counts come from NOAA’s station at Red Wing Dam 3, MN, 5 miles from the town’s center, 310 ft lower.
The 2023 USDA map puts Trenton’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −22°. 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 44 inches of snow a winter
Snow, measured at Red Wing, MN, is heaviest from January through February, about 10 inches a month. Precipitation (rain plus melted snow) adds up to 35 inches a year; June is the wettest month and January 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 Trenton
92% 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 Red Wing Dam 3, MN.
Living with Trenton’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
173 frost-free days in zone 4b. The last frost comes by Apr 23 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 14.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 1.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Trenton from natural hazards, river flooding is the largest share (50%); heat waves, cold waves, winter storms and ice storms together are 10%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Trenton and its neighbors
Diamond Bluff the hottest July afternoons (83°, 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 Trenton’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 |
|---|---|---|---|---|
| Trenton, WI | 7° | 81° | 35" | 44" |
| Plattsburgh, NY | 9° | 81° | 35" | 50" |
| Worthington, MN | 6° | 83° | 30" | 45" |
| Spirit Lake, IA | 7° | 83° | 31" | 42" |
| 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 Trenton averaged 1.1° warmer than the 1900s. The biggest change is in December (+3.0°).
A smaller shift than in 72% 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 Trenton compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Trenton’s place among Wisconsin’s.
Trenton weather by month
Highs, lows and precipitation from NOAA’s grid at Trenton’s center; snow, wet days and snow on the ground from Red Wing, MN. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 22° | 7° | 1.0" | 10.7" | 9 | 24 | 4° – 28° |
| February | 28° | 10° | 1.0" | 10.0" | 7 | 21 | 5° – 31° |
| March | 40° | 22° | 1.8" | 8.4" | 8 | 14 | 22° – 48° |
| April | 55° | 35° | 3.0" | 2.4" | 11 | 2 | 34° – 53° |
| May | 68° | 47° | 4.3" | 0.0" | 13 | 0 | 52° – 65° |
| June | 77° | 57° | 5.3" | 0.0" | 13 | 0 | 63° – 71° |
| July | 81° | 61° | 4.3" | 0.0" | 11 | 0 | 65° – 77° |
| August | 79° | 59° | 4.7" | 0.0" | 10 | 0 | 64° – 73° |
| September | 71° | 51° | 3.5" | 0.0" | 9 | 0 | 54° – 66° |
| October | 57° | 38° | 2.8" | 0.1" | 10 | 0 | 42° – 54° |
| November | 41° | 25° | 1.7" | 3.8" | 8 | 4 | 23° – 45° |
| December | 28° | 14° | 1.2" | 8.7" | 8 | 17 | 7° – 30° |
| Year | 54° | 35° | 34.5" | 44.1" | 118 | 82 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 5° to 31°. June is the most reliable, staying within 8°.
Where Trenton’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 Trenton’s center.
- Snow: Red Wing, MN.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Red Wing Dam 3, MN, 5 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 Trenton’s climate
What is the weather like in Trenton?
A typical July afternoon reaches 81°, a January night drops to 7°, and about 44 inches of snow falls in a normal winter. Colder January nights than 97% of U.S. towns; cooler July afternoons than 86% of U.S. towns.
How cold does it get in Trenton in winter?
January nights average 7°. About 154 nights a year reach 32° or below and 27 reach 0° or below. In the coldest January of the last 30 years the month averaged 4°.
How much snow does Trenton get?
About 44 inches in a normal winter at Red Wing, MN, heaviest from January through February, about 10 inches a month, with snow on the ground about 82 days a year.
How hot does it get in Trenton?
July, with a typical high of 81° and a low of 61°. About 11 days a year reach 90° (Red Wing Dam 3, MN).
When is the first and last frost in Trenton?
In half of years the last spring frost (32°) comes by April 23 and the first fall frost by October 14, about 173 frost-free days, at Red Wing Dam 3, MN.
What growing zone is Trenton in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −22°.
What is the best time of year to visit Trenton?
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 Trenton getting warmer?
Yes: 1991–2020 averaged 1.1° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 72% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Trenton.
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.