Photo: Tony Webster from San Francisco, California · CC BY-SA 2.0Duluth’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 76°, a January night drops to 5°, and about 56 inches of snow falls in a normal winter.
A year in Duluth at a glance
Each month’s typical high and low, and what it brings.
What stands out about Duluth’s climate
Compared with towns across the U.S., with Duluth’s place in Minnesota beside it.
What a year in Duluth feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 154 frost-free days a year
In half of years the last 32° night comes by May 6 and the first by October 9. Frost and day counts come from NOAA’s station at Superior, WI, 4 miles from the city’s center point, 410 ft lower.
The 2023 USDA map puts Duluth’s center in zone 4b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −23°. 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 56 inches of snow a winter
Snow, measured at Superior, WI, falls mostly in January. Precipitation (rain plus melted snow) adds up to 30 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 106 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Duluth
97% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Superior, WI.
Living with Duluth’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
154 frost-free days in zone 4b. The last frost comes by May 6 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 9.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 173 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Duluth from natural hazards, river flooding is the largest share (85%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Duluth and its neighbors
Canosia Township has the coldest January nights next door (0°, 5° colder) and Superior the hottest July afternoons (79°, 3° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Duluth’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 |
|---|---|---|---|---|
| Duluth, MN | 5° | 76° | 30" | 56" |
| Antigo, WI | 5° | 79° | 32" | 54" |
| Escanaba, MI | 11° | 77° | 30" | 47" |
| Plattsburgh, NY | 9° | 80° | 34" | 50" |
| Littleton, NH | 6° | 80° | 40" | 68" |
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 Duluth averaged 1.9° warmer than the 1900s. The biggest change is in January (+3.7°).
A bigger shift than in 84% 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 Duluth compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Duluth’s place among Minnesota’s.
Duluth weather by month
Highs, lows and precipitation from NOAA’s grid at Duluth’s center; snow, wet days and snow on the ground from Superior, WI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 21° | 5° | 1.0" | 14.5" | 7 | 26 | −1° – 26° |
| February | 26° | 7° | 0.9" | 12.4" | 6 | 26 | 6° – 30° |
| March | 36° | 17° | 1.4" | 9.1" | 7 | 19 | 18° – 39° |
| April | 47° | 29° | 2.5" | 1.7" | 9 | 4 | 31° – 45° |
| May | 60° | 39° | 3.2" | 0.0" | 12 | 0 | 44° – 54° |
| June | 70° | 49° | 4.3" | 0.0" | 12 | 0 | 56° – 63° |
| July | 76° | 56° | 4.0" | 0.0" | 10 | 0 | 60° – 72° |
| August | 74° | 55° | 3.6" | 0.0" | 10 | 0 | 59° – 68° |
| September | 66° | 47° | 3.3" | 0.0" | 10 | 0 | 49° – 61° |
| October | 52° | 36° | 3.0" | 0.2" | 10 | 0 | 38° – 48° |
| November | 37° | 23° | 1.8" | 5.8" | 8 | 7 | 21° – 41° |
| December | 25° | 11° | 1.3" | 12.3" | 7 | 20 | 6° – 28° |
| Year | 49° | 31° | 30.3" | 56.0" | 106 | 101 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from -1° to 26°. June is the most reliable, staying within 7°.
Where Duluth’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 Duluth’s center.
- Snow: Superior, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Superior, WI, 4 miles from the city’s center point, 410 ft lower; 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 Duluth’s climate
What is the weather like in Duluth?
A typical July afternoon reaches 76°, a January night drops to 5°, and about 56 inches of snow falls in a normal winter. Colder January nights than all but 181 U.S. towns; cooler July afternoons than 98% of U.S. towns.
How cold does it get in Duluth in winter?
January nights average 5°. About 161 nights a year reach 32° or below and 28 reach 0° or below. In the coldest January of the last 30 years the month averaged −1°.
How much snow does Duluth get?
About 56 inches in a normal winter at Superior, WI, most of it in January, with snow on the ground about 101 days a year.
How hot does it get in Duluth?
July, with a typical high of 76° and a low of 56°. About 3 days a year reach 90° (Superior, WI).
When is the first and last frost in Duluth?
In half of years the last spring frost (32°) comes by May 6 and the first fall frost by October 9, about 154 frost-free days, at Superior, WI.
What growing zone is Duluth in?
Zone 4b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −23°.
What is the best time of year to visit Duluth?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Duluth getting warmer?
Yes: 1991–2020 averaged 1.9° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 84% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Duluth.
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.