Grand Portage, Minnesota climate: Climate normals at a NOAA weather station
Grand Portage's normal year runs from 1°F January nights to 74°F July afternoons, with 30.6 inches of precipitation and 55 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 3.4°C, January lows of −17°C, July highs of 23°C, 776 mm of precipitation a year.
- NOAA stationGrand Portage
- Station IDUSC00213296
- Location47.97°N 89.69°W
- Elevation730 ft (223 m)
On October 23, the normal high in Grand Portage is 48°F and the normal low 31°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Grand Portage.
- Jan 20° 1°
- Feb 24° 2°
- Mar 34° 13°
- Apr 45° 26°
- May 58° 37°
- Jun 68° 46°
- Jul 74° 52°
- Aug 73° 52°
- Sep 65° 44°
- Oct 51° 33°
- Nov 38° 22°
- Dec 26° 9°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Grand Portage each month?
July is the warmest month, with normal highs of 74°F; January the coldest, with normal lows of 1°F. The most precipitation falls in June (3.58 in), the least in February (1.03 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 20°F | 1°F | 10.5°F | 1.35 | 12.2 | 9 | <1 | 31 | 8 h 50 min |
| February | 24°F | 2°F | 13.1°F | 1.03 | 8.0 | 6 | <1 | 28 | 10 h 10 min |
| March | 34°F | 13°F | 23.7°F | 1.33 | 8.0 | 7 | <1 | 30 | 11 h 50 min |
| April | 45°F | 26°F | 35.8°F | 2.79 | 7.7 | 9 | <1 | 25 | 13 h 40 min |
| May | 58°F | 37°F | 47.4°F | 3.11 | 0.2 | 11 | <1 | 9 | 15 h 10 min |
| June | 68°F | 46°F | 56.9°F | 3.58 | 0.0 | 12 | <1 | <1 | 16 h |
| July | 74°F | 52°F | 63.0°F | 3.42 | 0.0 | 12 | <1 | <1 | 15 h 40 min |
| August | 73°F | 52°F | 62.6°F | 3.04 | 0.0 | 10 | <1 | <1 | 14 h 20 min |
| September | 65°F | 44°F | 54.4°F | 3.13 | 0.0 | 12 | <1 | 2 | 12 h 40 min |
| October | 51°F | 33°F | 42.4°F | 3.40 | 0.5 | 11 | <1 | 15 | 11 h |
| November | 38°F | 22°F | 29.6°F | 2.65 | 6.7 | 9 | <1 | 26 | 9 h 20 min |
| December | 26°F | 9°F | 17.5°F | 1.74 | 11.9 | 9 | <1 | 31 | 8 h 20 min |
| Year (annual) | 48°F | 28°F | 38.1°F | 30.57 | 55.2 | 116 | 1 | 196 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −6°C | −17°C | −11.9°C | 34 mm | 31 cm |
| February | −4°C | −17°C | −10.5°C | 26 mm | 20 cm |
| March | 1°C | −11°C | −4.6°C | 34 mm | 20 cm |
| April | 7°C | −3°C | 2.1°C | 71 mm | 20 cm |
| May | 15°C | 3°C | 8.6°C | 79 mm | 1 cm |
| June | 20°C | 8°C | 13.8°C | 91 mm | 0 cm |
| July | 23°C | 11°C | 17.2°C | 87 mm | 0 cm |
| August | 23°C | 11°C | 17.0°C | 77 mm | 0 cm |
| September | 18°C | 7°C | 12.4°C | 80 mm | 0 cm |
| October | 11°C | 1°C | 5.8°C | 86 mm | 1 cm |
| November | 3°C | −6°C | −1.3°C | 67 mm | 17 cm |
| December | −3°C | −13°C | −8.1°C | 44 mm | 30 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00213296; 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.
Which months are mildest at Grand Portage?
Normal highs sit between 65°F and 85°F in June, July and August. Of those, August has the fewest days with rain (10).
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 USC00213296.
When is the last frost at Grand Portage?
In Grand Portage, the last spring frost (32°F) comes after May 24 in half of years and after June 5 in one year in ten; the first autumn frost comes before September 29 in half of years and before September 16 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 241 year in 10 after June 5; 9 in 10 after May 7
- First autumn frost, half of years before
- September 291 year in 10 before September 16; 9 in 10 before October 10
NOAA puts the median frost-free season at 127 days, and the season without a hard freeze (28°F) at 153 days.
A hard freeze (28°F) comes after May 9 in half of springs and before October 9 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Grand Portage in zone 4b in ZIP code 55605, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 4b: the coldest night of a typical year reaches −23°F (19 complete years).
Frost dates for every NOAA station in Minnesota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00213296; 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 at Grand Portage?
In a normal year in Grand Portage, 1 day a year reaches 90°F, 196 nights fall to 32°F or colder and 116 days bring measurable precipitation.
- 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
- 196a normal year
- Days that stay below freezing
- 92high of 32°F or less
- Days with 0.01 inch of precipitation
- 116a normal year
- Days with 1 inch of snow or more
- 21a normal year
The highest temperature in this station's record (since 1895) is 97°F, on July 15, 2026; the lowest is −33°F, on January 15, 1972.
The wettest calendar year on that record is 2019, with 39.96 in; the snowiest season is 2021–22, with 119.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00213296; records: ACIS (NOAA Regional Climate Centers), station USC00213296. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Grand Portage?
Over a year 68% of the sunlight that would reach the ground under clear skies gets through the clouds at Grand Portage, 3.4 kWh per square metre a day. July is the sunniest month (78%) and December the cloudiest (45%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 47% | 1.0 |
| February | 56% | 1.9 |
| March | 67% | 3.3 |
| April | 69% | 4.6 |
| May | 69% | 5.4 |
| June | 73% | 6.0 |
| July | 78% | 6.0 |
| August | 77% | 5.1 |
| September | 72% | 3.7 |
| October | 62% | 2.2 |
| November | 52% | 1.2 |
| December | 45% | 0.8 |
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 many heating and cooling degree days does Grand Portage record?
A normal year at Grand Portage brings 9,862 heating degree days, 84% more than the median U.S. place (5,373), and 85 cooling degree days, 91% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,256 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,689 | 0 |
| February | 1,452 | 0 |
| March | 1,280 | 0 |
| April | 876 | 0 |
| May | 545 | 0 |
| June | 250 | 7 |
| July | 103 | 39 |
| August | 110 | 34 |
| September | 322 | 4 |
| October | 702 | 0 |
| November | 1,061 | 0 |
| December | 1,473 | 0 |
| Year (annual) | 9,862 | 85 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00213296. 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.
Have recent years at Grand Portage been warmer than normal?
2025 averaged 38.3°F, 0.2°F above the 1991-2020 normal of 38.1°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 40.6°F | +2.5°F | 27.88 | 60.7 |
| 2022 | 36.4°F | −1.7°F | 39.87 | 131.7 |
| 2023 | 40.4°F | +2.3°F | 28.40 | 57.0 |
| 2024 | 41.7°F | +3.6°F | 31.42 | 49.4 |
| 2025 | 38.3°F | +0.2°F | – | – |
Source: observed years: ACIS, station USC00213296. A year counts only with all twelve months complete.
How does Grand Portage's climate compare?
Grand Portage is warmer than 11 of the 129 places with their own NOAA record in Minnesota, and wetter than 66. Across the 7,247 U.S. stations with normals, its annual mean of 38.1°F is warmer than 3%.
In the Köppen classification computed from these normals, Grand Portage 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.
Questions about Grand Portage's climate
What is the coldest month at Grand Portage?
January, with a normal high of 20°F and a normal low of 1°F. The warmest is July (74°F by day, 52°F at night).
Does it snow at Grand Portage?
Yes: 55 inches in a normal year, falling on 33 days with 0.1 inch or more, the most in January (12.2 inches).
What is the rainiest month at Grand Portage?
June, with 3.58 in of precipitation in a normal year; the driest is February with 1.03 in.
What plant hardiness zone is Grand Portage in?
The USDA's 2023 map puts Grand Portage in zone 4b in ZIP code 55605, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −23°F (19 years, 1991-2020): zone 4b.
How late can frost come at Grand Portage?
In half of years the last 32°F night comes after May 24; in one year in ten it comes after June 5. Waiting until June 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Minnesota climateThe statewide normals and every place in the state
- Grand Marais, MN34 miles from this station, 39.5°F a year
- Lutsen, MN49 miles from this station, 36.7°F a year
- Gunflint Lake (10 mi NW), MN57 miles from this station, 36.7°F a year
- Hancock, MI79 miles from this station, 40.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made