Superior, WI climate
Superior has cold, snowy winters and pleasant summers. A typical July afternoon reaches 79°, a January night drops to 3°, and about 90 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Superior feels like
Winter
Spring
Summer
Fall
Superior weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 21° | 3° | 0.9" | 16.8" | 10 | 31 | -1° – 26° |
| February | 27° | 6° | 0.9" | 15.1" | 9 | 28 | 6° – 31° |
| March | 38° | 18° | 1.4" | 12.8" | 10 | 27 | 19° – 41° |
| April | 51° | 30° | 2.5" | 9.1" | 11 | 10 | 33° – 47° |
| May | 64° | 40° | 3.3" | 0.8" | 13 | 0 | 47° – 57° |
| June | 73° | 49° | 4.2" | 0 | 12 | 0 | 57° – 64° |
| July | 79° | 56° | 4.0" | 0 | 12 | 0 | 61° – 74° |
| August | 77° | 55° | 3.7" | 0 | 11 | 0 | 61° – 69° |
| September | 69° | 47° | 3.2" | 0.1" | 12 | 0 | 51° – 62° |
| October | 55° | 36° | 3.0" | 2.7" | 12 | 2 | 39° – 49° |
| November | 39° | 23° | 1.8" | 14.1" | 11 | 13 | 22° – 41° |
| December | 26° | 11° | 1.3" | 18.7" | 11 | 27 | 6° – 28° |
| Year | 52° | 31° | 30.1" | 90.2" | 133 | 137 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Superior
Superior gets 30 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 133 days a year. Snow covers the ground about 137 days of the year.
About 135 frost-free days a year
In half of years the last 32° night comes by May 18 and the first one by October 3. That leaves about 135 frost-free days for gardens, shorter than 92% of U.S. towns.
Heating and cooling a home in Superior
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Superior, 97% of that work is heating and 3% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Superior and its neighbors
Superior borders 9 towns with climate data. January nights across them vary by 4.9°. Twin Lakes has the coldest January nights (1°) and Silver Brook the hottest July afternoons (79°). Superior’s January low is 3° and its July high 79°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Superior compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Superior averaged 1.8° warmer than the 1900s. The biggest change is in January (+3.7°). The shift is larger than in 89% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Superior’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from -1° to 26°. June is the most reliable, staying within 7°.
Common questions about Superior’s climate
What is the coldest month in Superior?
January, with a typical high of 21° and a low of 3°.
What is the hottest month in Superior?
July, with a typical high of 79° and a low of 56°. About 4 days a year reach 90°.
How much snow does Superior get?
About 90 inches in a normal winter, most of it in December.
When is the first frost in Superior?
In half of years the first 32° night comes by October 3, and the last spring frost by May 18.
What is the rainiest month in Superior?
June, with 4.2 inches of rain and melted snow. The year totals 30 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Superior itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Duluth, MN (18 mi, snow) and Pattison Ranger Staion, WI (4 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.