Hermantown, Minnesota climate: Normal weather by month, frost dates and records
Hermantown's normal year runs from 1°F January nights to 76°F July afternoons, with 30.9 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.3°C, January lows of −17°C, July highs of 25°C, 786 mm of precipitation a year.
- NOAA stationDuluth NWS
- Station IDUSC00212250
- Location46.84°N 92.21°W
- Elevation1,433 ft (437 m)
- Population10,265
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hermantown.
- Jan 18° 1°
- Feb 24° 4°
- Mar 36° 17°
- Apr 49° 29°
- May 63° 40°
- Jun 71° 50°
- Jul 76° 56°
- Aug 75° 55°
- Sep 66° 47°
- Oct 52° 36°
- Nov 35° 22°
- Dec 23° 8°
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 Hermantown each month?
July is the warmest month, with normal highs of 76°F; January the coldest, with normal lows of 1°F. The most precipitation falls in June (4.49 in), the least in January (0.92 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 18°F | 1°F | 9.4°F | 0.92 | – | <1 | 31 | 9 h |
| February | 24°F | 4°F | 14.1°F | 0.95 | – | <1 | 28 | 10 h 20 min |
| March | 36°F | 17°F | 26.5°F | 1.35 | – | <1 | 28 | 11 h 50 min |
| April | 49°F | 29°F | 38.7°F | 2.50 | – | <1 | 23 | 13 h 30 min |
| May | 63°F | 40°F | 51.6°F | 3.20 | – | <1 | 6 | 15 h |
| June | 71°F | 50°F | 60.5°F | 4.49 | – | <1 | <1 | 15 h 50 min |
| July | 76°F | 56°F | 66.2°F | 4.13 | – | 1 | <1 | 15 h 30 min |
| August | 75°F | 55°F | 65.0°F | 3.55 | – | <1 | <1 | 14 h 20 min |
| September | 66°F | 47°F | 56.7°F | 3.50 | – | <1 | 1 | 12 h 40 min |
| October | 52°F | 36°F | 43.9°F | 3.02 | – | <1 | 11 | 11 h |
| November | 35°F | 22°F | 28.4°F | 1.98 | – | <1 | 26 | 9 h 30 min |
| December | 23°F | 8°F | 15.5°F | 1.34 | – | <1 | 31 | 8 h 30 min |
| Year (annual) | 49°F | 30°F | 39.7°F | 30.93 | – | 1 | 184 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −8°C | −17°C | −12.6°C | 23 mm |
| February | −5°C | −15°C | −9.9°C | 24 mm |
| March | 2°C | −8°C | −3.1°C | 34 mm |
| April | 9°C | −2°C | 3.7°C | 64 mm |
| May | 17°C | 5°C | 10.9°C | 81 mm |
| June | 22°C | 10°C | 15.8°C | 114 mm |
| July | 25°C | 13°C | 19.0°C | 105 mm |
| August | 24°C | 13°C | 18.3°C | 90 mm |
| September | 19°C | 8°C | 13.7°C | 89 mm |
| October | 11°C | 2°C | 6.6°C | 77 mm |
| November | 2°C | −6°C | −2.0°C | 50 mm |
| December | −5°C | −13°C | −9.2°C | 34 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Duluth (0 miles away), gets 90 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00212250; 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 Hermantown?
Normal highs sit between 65°F and 85°F in 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 USC00212250.
When is the last frost in Hermantown?
In Hermantown, the last spring frost (32°F) comes after May 18 in half of years and after June 3 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 19 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 181 year in 10 after June 3; 9 in 10 after May 2
- First autumn frost, half of years before
- October 11 year in 10 before September 19; 9 in 10 before October 14
NOAA puts the median frost-free season at 135 days, and the season without a hard freeze (28°F) at 159 days.
A hard freeze (28°F) comes after May 4 in half of springs and before October 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hermantown in zone 4b across its 2 ZIP code areas (4b in 55811, the largest).
Frost dates for every NOAA station in Minnesota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00212250; 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.
What hardiness zone is each Hermantown ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Hermantown's 2 ZIP code areas are all in zone 4b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Hermantown?
In a normal year in Hermantown, 1 day a year reaches 90°F and 184 nights fall to 32°F or colder.
- Days at 90°F or more
- 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 184a normal year
- Days that stay below freezing
- 108high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00212250.
How sunny is Hermantown?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hermantown, 3.7 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 1.6 |
| February | 76% | 2.7 |
| March | 73% | 3.8 |
| April | 69% | 4.7 |
| May | 68% | 5.4 |
| June | 72% | 5.9 |
| July | 79% | 6.2 |
| August | 77% | 5.2 |
| September | 72% | 3.8 |
| October | 65% | 2.4 |
| November | 63% | 1.5 |
| December | 60% | 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 Hermantown need?
A normal year in Hermantown brings 9,382 heating degree days, 75% more than the median U.S. place (5,373), and 191 cooling degree days, 79% 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 1,706 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,723 | 0 |
| February | 1,426 | 0 |
| March | 1,195 | 0 |
| April | 790 | 0 |
| May | 420 | 4 |
| June | 158 | 21 |
| July | 50 | 86 |
| August | 66 | 65 |
| September | 264 | 14 |
| October | 656 | 0 |
| November | 1,098 | 0 |
| December | 1,536 | 0 |
| Year (annual) | 9,382 | 191 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00212250. 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 Hermantown been warmer than normal lately?
2025 averaged 39.8°F, 0.1°F above the 1991-2020 normal of 39.7°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 41.9°F | +2.2°F | 26.32 |
| 2022 | 37.3°F | −2.4°F | 33.33 |
| 2023 | 41.3°F | +1.6°F | 30.88 |
| 2024 | 43.3°F | +3.6°F | 27.85 |
| 2025 | 39.8°F | +0.1°F | 20.51 |
Source: observed years: ACIS, station USC00212250. A year counts only with all twelve months complete.
How does Hermantown's climate compare?
Hermantown is warmer than 22 of the other 128 places with their own NOAA record in Minnesota, and wetter than 70. Across the 7,247 U.S. stations with normals, its annual mean of 39.7°F is warmer than 5%.
In the Köppen classification computed from these normals, Hermantown 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 Hermantown share this climate record?
Oliver has no NOAA station with 1991-2020 normals of its 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.
- Oliver, WI417 people · 13 mi S
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 Hermantown's climate
What is the coldest month in Hermantown?
January, with a normal high of 18°F and a normal low of 1°F. The warmest is July (76°F by day, 56°F at night).
Does it snow in Hermantown?
Yes. NOAA publishes no 1991-2020 snowfall normal for Hermantown's NOAA station; the nearest record that keeps one, Duluth (0 miles away), records 90 inches of snow in a normal year.
What is the rainiest month in Hermantown?
June, with 4.49 in of precipitation in a normal year; the driest is January with 0.92 in.
What plant hardiness zone is Hermantown in?
The USDA's 2023 map puts Hermantown in zone 4b across its 2 ZIP code areas (4b in 55811, the largest).
How late can frost come in Hermantown?
In half of years the last 32°F night comes after May 18; in one year in ten it comes after June 3. Waiting until June 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Minnesota climateThe statewide normals and every place in the state
- Duluth, MN0 miles from this station, 40.6°F a year
- Superior, WI10 miles from this station, 41.4°F a year
- Island Lake (4 mi E), MN14 miles from this station, 38.9°F a year
- Cloquet, MN17 miles from this station, 39.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made