Mahnomen, Minnesota climate: Normal weather by month, frost dates and records
Mahnomen's normal year runs from −2°F January nights to 79°F July afternoons, with 26.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.4°C, January lows of −19°C, July highs of 26°C, 671 mm of precipitation a year.
- NOAA stationMahnomen
- Station IDUSC00215012
- Location47.32°N 95.97°W
- Elevation1,212 ft (369 m)
- Population1,216
On October 22, the normal high in Mahnomen is 49°F and the normal low 32°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mahnomen.
- Jan 15° -2°
- Feb 21° 2°
- Mar 34° 15°
- Apr 52° 30°
- May 66° 43°
- Jun 74° 54°
- Jul 79° 58°
- Aug 78° 55°
- Sep 69° 47°
- Oct 54° 34°
- Nov 34° 20°
- Dec 22° 6°
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 Mahnomen each month?
July is the warmest month, with normal highs of 79°F; January the coldest, with normal lows of −2°F. The most precipitation falls in June (4.72 in), the least in February (0.73 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 15°F | −2°F | 6.3°F | 0.79 | – | <1 | 31 | 8 h 50 min |
| February | 21°F | 2°F | 11.4°F | 0.73 | – | <1 | 27 | 10 h 10 min |
| March | 34°F | 15°F | 24.8°F | 1.08 | – | <1 | 28 | 11 h 50 min |
| April | 52°F | 30°F | 40.9°F | 1.71 | – | <1 | 19 | 13 h 30 min |
| May | 66°F | 43°F | 54.6°F | 3.15 | – | <1 | 4 | 15 h |
| June | 74°F | 54°F | 63.8°F | 4.72 | – | 1 | <1 | 15 h 50 min |
| July | 79°F | 58°F | 68.1°F | 3.76 | – | 2 | <1 | 15 h 40 min |
| August | 78°F | 55°F | 66.5°F | 3.44 | – | 2 | <1 | 14 h 20 min |
| September | 69°F | 47°F | 57.9°F | 2.76 | – | <1 | 3 | 12 h 40 min |
| October | 54°F | 34°F | 43.9°F | 2.26 | – | <1 | 14 | 11 h |
| November | 34°F | 20°F | 26.8°F | 0.96 | – | <1 | 28 | 9 h 20 min |
| December | 22°F | 6°F | 13.6°F | 1.05 | – | <1 | 31 | 8 h 30 min |
| Year (annual) | 50°F | 30°F | 39.9°F | 26.41 | – | 5 | 185 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −9°C | −19°C | −14.3°C | 20 mm |
| February | −6°C | −17°C | −11.4°C | 19 mm |
| March | 1°C | −9°C | −4.0°C | 27 mm |
| April | 11°C | −1°C | 4.9°C | 43 mm |
| May | 19°C | 6°C | 12.6°C | 80 mm |
| June | 23°C | 12°C | 17.7°C | 120 mm |
| July | 26°C | 14°C | 20.1°C | 96 mm |
| August | 26°C | 13°C | 19.2°C | 87 mm |
| September | 21°C | 8°C | 14.4°C | 70 mm |
| October | 12°C | 1°C | 6.6°C | 57 mm |
| November | 1°C | −7°C | −2.9°C | 24 mm |
| December | −6°C | −15°C | −10.2°C | 27 mm |
NOAA publishes no 1991-2020 snowfall normal for this station, and no record within 25 miles keeps one, so snow is left out here rather than estimated.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00215012; 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 Mahnomen?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
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 USC00215012.
When is the last frost in Mahnomen?
In Mahnomen, the last spring frost (32°F) comes after May 7 in half of years and after May 24 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 15 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 71 year in 10 after May 24; 9 in 10 after April 27
- First autumn frost, half of years before
- September 281 year in 10 before September 15; 9 in 10 before October 13
NOAA puts the median frost-free season at 143 days, and the season without a hard freeze (28°F) at 162 days.
A hard freeze (28°F) comes after April 29 in half of springs and before October 8 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mahnomen in zone 4a in ZIP code 56557, the nearest ZIP area.
Frost dates for every NOAA station in Minnesota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00215012; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Mahnomen?
In a normal year in Mahnomen, 5 days a year reach 90°F and 185 nights fall to 32°F or colder.
- Days at 90°F or more
- 5a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 185a normal year
- Days that stay below freezing
- 100high of 32°F or less
The highest temperature in this station's record (since 1927) is 103°F, on August 19, 1976; the lowest is −53°F, on February 1, 1996.
The wettest calendar year on that record is 1994, with 29.21 in; the snowiest season is 1996–97, with 92.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00215012; records: ACIS (NOAA Regional Climate Centers), station USC00215012. Records use complete months only; a month missing more than three days is left out.
How sunny is Mahnomen?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Mahnomen, 3.7 kWh per square metre a day. February is the sunniest month (80%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 73% | 1.6 |
| February | 80% | 2.8 |
| March | 75% | 3.9 |
| April | 71% | 4.8 |
| May | 69% | 5.4 |
| June | 72% | 5.9 |
| July | 79% | 6.2 |
| August | 78% | 5.2 |
| September | 72% | 3.8 |
| October | 65% | 2.4 |
| November | 62% | 1.4 |
| December | 62% | 1.1 |
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 Mahnomen need?
A normal year in Mahnomen brings 9,470 heating degree days, 76% more than the median U.S. place (5,373), and 362 cooling degree days, 60% 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 2,046 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,818 | 0 |
| February | 1,501 | 0 |
| March | 1,246 | 0 |
| April | 724 | 0 |
| May | 341 | 20 |
| June | 105 | 70 |
| July | 34 | 128 |
| August | 58 | 106 |
| September | 248 | 35 |
| October | 656 | 4 |
| November | 1,146 | 0 |
| December | 1,595 | 0 |
| Year (annual) | 9,470 | 362 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00215012. 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 Mahnomen been warmer than normal lately?
2025 averaged 41.0°F, 1.1°F above the 1991-2020 normal of 39.9°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2025 | 41.0°F | +1.1°F | 28.82 |
Over 40 complete years from 1960 to 2025, the station's annual mean temperature rose at a fitted 5.3°F per century (+0.29°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00215012; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Mahnomen's climate compare?
Mahnomen is warmer than 26 of the other 128 places with their own NOAA record in Minnesota, and wetter than 20. Across the 7,247 U.S. stations with normals, its annual mean of 39.9°F is warmer than 5%.
In the Köppen classification computed from these normals, Mahnomen 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 Mahnomen share this climate record?
10 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.
- Naytahwaush, MN443 people · 16 mi E
- Waubun, MN399 people · 9 mi S
- Riverland, MN273 people · 1 mi NE
- Twin Lakes, MN231 people · 16 mi SE
- Ogema, MN205 people · 15 mi S
- Bejou, MN83 people · 9 mi N
- Beaulieu, MN50 people · 7 mi E
- West Roy Lake, MN42 people · 18 mi E
- Midway, MN35 people · 9 mi E
- The Ranch, MN3 people · 13 mi E
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 Mahnomen's climate
What is the coldest month in Mahnomen?
January, with a normal high of 15°F and a normal low of −2°F. The warmest is July (79°F by day, 58°F at night).
What is the rainiest month in Mahnomen?
June, with 4.72 in of precipitation in a normal year; the driest is February with 0.73 in.
What plant hardiness zone is Mahnomen in?
The USDA's 2023 map puts Mahnomen in zone 4a in ZIP code 56557, the nearest ZIP area.
How late can frost come in Mahnomen?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 24. Waiting until May 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Minnesota climateThe statewide normals and every place in the state
- Fosston, MN21 miles from this station, 38.8°F a year
- Ada, MN25 miles from this station, 40.0°F a year
- Tamarac Wildlife Re, MN29 miles from this station, 40.9°F a year
- Detroit Lakes, MN34 miles from this station, 40.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made