Matt Johnson Log House · Photo: Csgaylord · CC BY-SA 3.0Few U.S. towns have colder winter nights than Knox
The warmest part of a July day comes in at 77° on average. The seasons are far apart: from a winter night to a summer afternoon the average spans 74°. By July afternoons alone, it runs cooler than 97% of U.S. towns. The outdoor season runs from May to September, with highs of 65–77°.
A year in Knox at a glance
Each month’s typical high and low, and what it brings.
What stands out about Knox’s climate
Compared with towns across the U.S., with Knox’s place in Wisconsin beside it.
What a year in Knox feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 124 frost-free days a year
In half of years the last 32° night comes by May 23 and the first by September 23. Frost and day counts come from NOAA’s station at Prentice #2, WI, 9 miles from the town’s center, 110 ft lower.
The 2023 USDA map puts Knox’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 Knox
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 Prentice #2, WI.
Living with Knox’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
124 frost-free days in zone 4a. The last frost comes by May 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 Sep 23.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 2.8 miles of trails are waiting.
Parks & trails →Cold waves are 46% of the yearly building losses FEMA expects in Knox from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →Knox and its neighbors
Every town next door is within a degree of Knox in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Knox’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 |
|---|---|---|---|---|
| Knox, WI | 3° | 77° | 33" | 62" |
| Grand Rapids, MN | −2° | 79° | 28" | 60" |
| Beekmantown, NY | 9° | 80° | 35" | 80" |
| Littleton, NH | 6° | 80° | 40" | 68" |
| Gladstone, MI | 11° | 76° | 31" | 47" |
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 Knox averaged 1.6° warmer than the 1900s. The biggest change is in December (+3.5°).
A bigger shift than in 65% 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 Knox compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Knox’s place among Wisconsin’s.
Knox weather by month
Highs, lows and precipitation from NOAA’s grid at Knox’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 | 20° | 3° | 1.2" | 13.8" | 9 | 0° – 24° |
| February | 26° | 5° | 1.1" | 12.1" | 6 | 3° – 29° |
| March | 38° | 16° | 1.7" | 10.6" | 7 | 17° – 42° |
| April | 51° | 28° | 2.9" | 4.3" | 9 | 30° – 48° |
| May | 65° | 41° | 3.7" | 0.2" | 10 | 46° – 60° |
| June | 74° | 51° | 4.4" | 0.0" | 10 | 58° – 67° |
| July | 77° | 55° | 3.9" | 0.0" | 10 | 60° – 71° |
| August | 75° | 53° | 3.8" | 0.0" | 9 | 59° – 68° |
| September | 67° | 46° | 3.6" | 0.0" | 9 | 49° – 61° |
| October | 53° | 34° | 3.3" | 1.3" | 9 | 37° – 49° |
| November | 38° | 23° | 2.0" | 8.1" | 8 | 20° – 40° |
| December | 25° | 11° | 1.5" | 11.1" | 9 | 6° – 28° |
| Year | 51° | 31° | 33.1" | 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 29°. August is the most reliable, staying within 9°.
Where Knox’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 Knox’s center.
- Snow: Spirit Falls, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Prentice #2, WI, 9 miles from the town’s center, 110 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 Knox’s climate
What is the weather like in Knox?
A typical July afternoon reaches 77°, 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 97% of U.S. towns.
How cold does it get in Knox in winter?
January nights average 3°. About 190 nights a year reach 32° or below and 43 reach 0° or below. In the coldest January of the last 30 years the month averaged 0°.
How much snow does Knox get?
About 62 inches in a normal winter at Spirit Falls, WI, most of it in January.
How hot does it get in Knox?
July, with a typical high of 77° and a low of 55°. About 2 days a year reach 90° (Prentice #2, WI).
When is the first and last frost in Knox?
In half of years the last spring frost (32°) comes by May 23 and the first fall frost by September 23, about 124 frost-free days, at Prentice #2, WI.
What growing zone is Knox 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 Knox?
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 Knox getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 65% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Knox.
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.