Casselton Commercial Historic District · Photo: Andrew Filer (afiler) · CC BY-SA 2.0Few U.S. towns have colder winter nights than Casselton
Midsummer highs settle at about 82°. Rain follows the seasons: June brings about 7.5 times as much as February. By precipitation alone, it ranks drier than 88% of U.S. towns. Keep the boiler serviced for the months from October to April, which average under 50°.
A year in Casselton at a glance
Each month’s typical high and low, and what it brings.
What stands out about Casselton’s climate
Compared with towns across the U.S., with Casselton’s place in North Dakota beside it.
What a year in Casselton feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 143 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by October 1. Frost and day counts come from NOAA’s station at Casselton Agronomy Farm, ND, 1.7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Casselton’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 37 inches of snow a winter
Snow, measured at Casselton Agronomy Farm, ND, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 23 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 84 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Casselton
95% 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 Casselton Agronomy Farm, ND.
Living with Casselton’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
143 frost-free days in zone 4a. The last frost comes by May 9 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 1.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 0.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Casselton from natural hazards, river flooding is the largest share (27%); heat waves, cold waves, winter storms and ice storms together are 22%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Casselton and its neighbors
Every town next door is within a degree of Casselton in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Casselton’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 |
|---|---|---|---|---|
| Casselton, ND | 0° | 82° | 23" | 37" |
| Brookings, SD | 5° | 82° | 27" | 36" |
| Montevideo, MN | 4° | 83° | 28" | 46" |
| Sheldon, IA | 7° | 84° | 30" | 41" |
| Sidney, MT | 4° | 85° | 15" | 30" |
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 Casselton averaged 1.4° warmer than the 1900s. The biggest change is in January (+3.6°).
A bigger shift than in 52% 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 Casselton compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Casselton’s place among North Dakota’s.
Casselton weather by month
Highs, lows and precipitation from NOAA’s grid at Casselton’s center; snow, wet days and snow on the ground from Casselton Agronomy Farm, ND. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 18° | 0° | 0.6" | 7.4" | 4 | −5° – 24° |
| February | 23° | 4° | 0.5" | 6.6" | 5 | 0° – 27° |
| March | 37° | 18° | 1.0" | 6.2" | 5 | 17° – 42° |
| April | 55° | 32° | 1.4" | 3.3" | 6 | 33° – 51° |
| May | 69° | 44° | 3.1" | 0.0" | 11 | 51° – 63° |
| June | 78° | 55° | 4.0" | 0.0" | 11 | 62° – 71° |
| July | 82° | 59° | 3.5" | 0.0" | 9 | 64° – 76° |
| August | 81° | 56° | 2.7" | 0.0" | 8 | 62° – 73° |
| September | 72° | 47° | 2.5" | 0.0" | 7 | 54° – 65° |
| October | 56° | 35° | 2.1" | 0.7" | 7 | 37° – 52° |
| November | 38° | 20° | 0.7" | 4.4" | 5 | 17° – 41° |
| December | 24° | 7° | 0.7" | 8.1" | 5 | 0° – 25° |
| Year | 53° | 31° | 22.7" | 36.7" | 84 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from -5° to 24°. June is the most reliable, staying within 9°.
Where Casselton’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 Casselton’s center.
- Snow: Casselton Agronomy Farm, ND (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Casselton Agronomy Farm, ND, 1.7 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 Casselton’s climate
What is the weather like in Casselton?
A typical July afternoon reaches 82°, a January night drops to 0°, and about 37 inches of snow falls in a normal winter. Colder January nights than all but 41 U.S. towns; cooler July afternoons than 77% of U.S. towns.
How cold does it get in Casselton in winter?
January nights average 0°. About 182 nights a year reach 32° or below and 46 reach 0° or below. In the coldest January of the last 30 years the month averaged −5°.
How much snow does Casselton get?
About 37 inches in a normal winter at Casselton Agronomy Farm, ND, most of it in January and December.
How hot does it get in Casselton?
July, with a typical high of 82° and a low of 59°. About 10 days a year reach 90° (Casselton Agronomy Farm, ND).
When is the first and last frost in Casselton?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by October 1, about 143 frost-free days, at Casselton Agronomy Farm, ND.
What growing zone is Casselton 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 Casselton?
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 Casselton getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 52% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Casselton.
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.