Photo: Paltron · CC BY-SA 4.0Wet weather: 49 inches of rain and melted snow a year in Koshkonong, more than in 80% of U.S. towns
January mornings start at about 24°. The seasons are far apart: from a winter night to a summer afternoon the average spans 65°. By July afternoons alone, it runs hotter than 73% of U.S. towns. Tender plants can go out after about April 12; in half of years the first frost comes by October 24.
A year in Koshkonong at a glance
Each month’s typical high and low, and what it brings.
What stands out about Koshkonong’s climate
Compared with towns across the U.S., with Koshkonong’s place in Missouri beside it.
What a year in Koshkonong feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 194 frost-free days a year
In half of years the last 32° night comes by April 12 and the first by October 24. Frost and day counts come from NOAA’s station at Mammoth Spring, AR, 9 miles from the town’s center, 470 ft lower.
The 2023 USDA map puts Koshkonong’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 2°. 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 9 inches of snow a winter
Snow, measured at W Plains, MO, falls mostly in February. Precipitation (rain plus melted snow) adds up to 49 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 103 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Koshkonong
75% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Mammoth Spring, AR.
Living with Koshkonong’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
194 frost-free days in zone 7a. The last frost comes by Apr 12 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 24.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Koshkonong from natural hazards, river flooding is the largest share (36%); heat waves, cold waves, winter storms and ice storms together are 33%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Koshkonong and similar climates
TownRatings has no climate map of the towns around Koshkonong yet.
Climates most like Koshkonong’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 |
|---|---|---|---|---|
| Koshkonong, MO | 24° | 89° | 49" | 8.7" |
| Harrisburg, IL | 25° | 88° | 48" | 7.2" |
| Highland, IN | 25° | 88° | 49" | 11" |
| Princeton, KY | 26° | 89° | 50" | 8.5" |
| Prairie Grove, AR | 26° | 90° | 48" | 6.5" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Koshkonong averaged 1.2° warmer than the 1900s. The biggest change is in February (+2.2°).
A smaller shift than in 60% 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 Koshkonong compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Koshkonong’s place among Missouri’s.
Koshkonong weather by month
Highs, lows and precipitation from NOAA’s grid at Koshkonong’s center; snow, wet days and snow on the ground from W Plains, MO. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 45° | 24° | 3.1" | 2.3" | 8 | 29° – 43° |
| February | 50° | 28° | 3.3" | 2.9" | 8 | 31° – 49° |
| March | 60° | 36° | 4.7" | 2.4" | 10 | 40° – 59° |
| April | 70° | 45° | 5.3" | 0.0" | 9 | 52° – 63° |
| May | 77° | 54° | 5.6" | 0.0" | 11 | 61° – 73° |
| June | 85° | 63° | 3.6" | 0.0" | 8 | 69° – 79° |
| July | 89° | 67° | 4.0" | 0.0" | 8 | 72° – 82° |
| August | 88° | 65° | 3.7" | 0.0" | 8 | 71° – 82° |
| September | 81° | 57° | 3.8" | 0.0" | 7 | 65° – 76° |
| October | 71° | 45° | 3.8" | 0.1" | 8 | 53° – 64° |
| November | 58° | 36° | 4.5" | 0.0" | 9 | 41° – 53° |
| December | 48° | 28° | 3.5" | 1.0" | 8 | 26° – 46° |
| Year | 69° | 46° | 48.8" | 8.7" | 103 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 26° to 46°. June is the most reliable, staying within 10°.
Where Koshkonong’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 Koshkonong’s center.
- Snow: W Plains, MO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mammoth Spring, AR, 9 miles from the town’s center, 470 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 Koshkonong’s climate
What is the weather like in Koshkonong?
A typical July afternoon reaches 89°, a January night drops to 24°, and about 9 inches of snow falls in a normal winter. Milder January nights than 61% of U.S. towns; hotter July afternoons than 73% of U.S. towns.
How cold does it get in Koshkonong in winter?
January nights average 24°. About 103 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 29°.
How much snow does Koshkonong get?
About 8.7 inches in a normal winter at W Plains, MO, most of it in February.
How hot does it get in Koshkonong?
July, with a typical high of 89° and a low of 67°. About 49 days a year reach 90° and 2 reach 100° (Mammoth Spring, AR).
When is the first and last frost in Koshkonong?
In half of years the last spring frost (32°) comes by April 12 and the first fall frost by October 24, about 194 frost-free days, at Mammoth Spring, AR.
What growing zone is Koshkonong in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 2°.
What is the best time of year to visit Koshkonong?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Koshkonong getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Koshkonong.
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.