Casselton, North Dakota climate: Normal weather by month, frost dates and records
Casselton's normal year runs from −1°F January nights to 81°F July afternoons, with 24.2 inches of precipitation and 37 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.1°C, January lows of −19°C, July highs of 27°C, 615 mm of precipitation a year.
- NOAA stationCasselton Agronomy Farm
- Station IDUSC00321408
- Location46.88°N 97.23°W
- Elevation935 ft (285 m)
- Population2,486
On October 14, the normal high in Casselton is 57°F and the normal low 35°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Casselton.
- Jan 17° -1°
- Feb 22° 2°
- Mar 35° 17°
- Apr 53° 31°
- May 68° 43°
- Jun 77° 55°
- Jul 81° 59°
- Aug 80° 56°
- Sep 71° 46°
- Oct 56° 34°
- Nov 38° 20°
- Dec 23° 7°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Casselton each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of −1°F. The most precipitation falls in June (4.43 in), the least in January (0.54 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 17°F | −1°F | 7.8°F | 0.54 | 7.4 | 4 | <1 | 31 | 8 h 50 min |
| February | 22°F | 2°F | 11.8°F | 0.57 | 6.6 | 5 | <1 | 28 | 10 h 20 min |
| March | 35°F | 17°F | 25.8°F | 1.09 | 6.2 | 5 | <1 | 28 | 11 h 50 min |
| April | 53°F | 31°F | 41.7°F | 1.49 | 3.3 | 6 | <1 | 18 | 13 h 30 min |
| May | 68°F | 43°F | 55.4°F | 3.16 | 0.0 | 11 | 1 | 3 | 15 h |
| June | 77°F | 55°F | 66.0°F | 4.43 | 0.0 | 11 | 2 | <1 | 15 h 50 min |
| July | 81°F | 59°F | 69.7°F | 3.69 | 0.0 | 9 | 3 | <1 | 15 h 30 min |
| August | 80°F | 56°F | 67.8°F | 2.62 | 0.0 | 8 | 3 | <1 | 14 h 20 min |
| September | 71°F | 46°F | 58.9°F | 2.79 | 0.0 | 7 | 1 | 2 | 12 h 40 min |
| October | 56°F | 34°F | 44.7°F | 2.33 | 0.7 | 7 | <1 | 14 | 11 h |
| November | 38°F | 20°F | 28.7°F | 0.80 | 4.4 | 5 | <1 | 27 | 9 h 30 min |
| December | 23°F | 7°F | 14.9°F | 0.69 | 8.1 | 5 | <1 | 31 | 8 h 30 min |
| Year (annual) | 52°F | 31°F | 41.1°F | 24.20 | 36.7 | 84 | 10 | 182 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −8°C | −19°C | −13.4°C | 14 mm | 19 cm |
| February | −6°C | −17°C | −11.2°C | 14 mm | 17 cm |
| March | 2°C | −9°C | −3.4°C | 28 mm | 16 cm |
| April | 12°C | −1°C | 5.4°C | 38 mm | 8 cm |
| May | 20°C | 6°C | 13.0°C | 80 mm | 0 cm |
| June | 25°C | 13°C | 18.9°C | 113 mm | 0 cm |
| July | 27°C | 15°C | 20.9°C | 94 mm | 0 cm |
| August | 27°C | 13°C | 19.9°C | 67 mm | 0 cm |
| September | 22°C | 8°C | 14.9°C | 71 mm | 0 cm |
| October | 13°C | 1°C | 7.1°C | 59 mm | 2 cm |
| November | 3°C | −7°C | −1.8°C | 20 mm | 11 cm |
| December | −5°C | −14°C | −9.5°C | 18 mm | 21 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00321408; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Casselton?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00321408.
When is the last frost in Casselton?
In Casselton, the last spring frost (32°F) comes after May 9 in half of years and after May 21 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 17 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 91 year in 10 after May 21; 9 in 10 after April 25
- First autumn frost, half of years before
- October 11 year in 10 before September 17; 9 in 10 before October 15
NOAA puts the median frost-free season at 143 days, and the season without a hard freeze (28°F) at 163 days.
A hard freeze (28°F) comes after April 29 in half of springs and before October 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Casselton in zone 4a in ZIP code 58012, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Casselton's NOAA station is in zone 4a: the coldest night of a typical year reaches −26°F (25 complete years).
Frost dates for every NOAA station in North Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00321408; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Casselton?
In a normal year in Casselton, 10 days a year reach 90°F, 182 nights fall to 32°F or colder and 84 days bring measurable precipitation.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 182a normal year
- Days that stay below freezing
- 94high of 32°F or less
- Days with 0.01 inch of precipitation
- 84a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1984) is 107°F, on July 6, 1988; the lowest is −39°F, on February 9, 1994.
The wettest calendar year on that record is 2019, with 30.06 in; the snowiest season is 1996–97, with 98.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00321408; records: ACIS (NOAA Regional Climate Centers), station USC00321408. Records use complete months only; a month missing more than three days is left out.
How sunny is Casselton?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Casselton, 3.9 kWh per square metre a day. February is the sunniest month (83%) and December the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 1.8 |
| February | 83% | 3.0 |
| March | 75% | 3.9 |
| April | 73% | 4.9 |
| May | 71% | 5.6 |
| June | 75% | 6.2 |
| July | 82% | 6.5 |
| August | 81% | 5.4 |
| September | 77% | 4.1 |
| October | 69% | 2.6 |
| November | 67% | 1.6 |
| December | 66% | 1.2 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Casselton need?
A normal year in Casselton brings 9,114 heating degree days, 70% more than the median U.S. place (5,373), and 449 cooling degree days, 51% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,246 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,775 | 0 |
| February | 1,488 | 0 |
| March | 1,215 | 0 |
| April | 699 | 0 |
| May | 318 | 21 |
| June | 69 | 98 |
| July | 21 | 167 |
| August | 39 | 127 |
| September | 218 | 35 |
| October | 632 | 3 |
| November | 1,088 | 0 |
| December | 1,553 | 0 |
| Year (annual) | 9,114 | 449 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00321408. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Casselton been warmer than normal lately?
2025 averaged 42.7°F, 1.6°F above the 1991-2020 normal of 41.1°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 43.8°F | +2.7°F | 16.07 | – |
| 2022 | 39.2°F | −1.9°F | 23.38 | – |
| 2024 | 45.2°F | +4.1°F | 22.90 | 19.1 |
| 2025 | 42.7°F | +1.6°F | 21.61 | – |
Source: observed years: ACIS, station USC00321408. A year counts only with all twelve months complete.
How does Casselton's climate compare?
Casselton is warmer than 43 of the other 91 places with their own NOAA record in North Dakota, and wetter than 72. Across the 7,247 U.S. stations with normals, its annual mean of 41.1°F is warmer than 8%.
In the Köppen classification computed from these normals, Casselton is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Casselton share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Leonard, ND245 people · 16 mi S
- Buffalo, ND189 people · 15 mi W
- Amenia, ND87 people · 9 mi N
- Wheatland, ND38 people · 6 mi W
- Embden, ND15 people · 11 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Casselton's climate
What is the coldest month in Casselton?
January, with a normal high of 17°F and a normal low of −1°F. The warmest is July (81°F by day, 59°F at night).
Does it snow in Casselton?
Yes: 37 inches in a normal year, falling on 17 days with 0.1 inch or more, the most in December (8.1 inches).
What is the rainiest month in Casselton?
June, with 4.43 in of precipitation in a normal year; the driest is January with 0.54 in.
What plant hardiness zone is Casselton in?
The USDA's 2023 map puts Casselton in zone 4a in ZIP code 58012, the nearest ZIP area. By the same method at Casselton's NOAA station, the coldest night of a typical year reaches −26°F (25 years, 1991-2020): zone 4a.
How late can frost come in Casselton?
In half of years the last 32°F night comes after May 9; in one year in ten it comes after May 21. Waiting until May 21 leaves about a one-in-ten chance of a later frost.
Nearby and next
- North Dakota climateThe statewide normals and every place in the state
- Fargo, ND20 miles from this station, 42.2°F a year
- Moorhead, MN23 miles from this station, 42.2°F a year
- Georgetown, MN25 miles from this station, 42.1°F a year
- Enderlin, ND26 miles from this station, 45.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made