South Arm, MI climate
South Arm has cold, snowy winters and pleasant summers. A typical July afternoon reaches 81°, a January night drops to 14°, and about 122 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in South Arm feels like
Winter
Spring
Summer
Fall
South Arm 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 | 28° | 14° | 2.4" | 37.4" | 17 | 29 | 10° – 30° |
| February | 30° | 13° | 1.6" | 23.1" | 12 | 28 | 7° – 32° |
| March | 40° | 20° | 1.8" | 11.0" | 10 | 21 | 20° – 44° |
| April | 53° | 31° | 2.9" | 4.6" | 11 | 3 | 33° – 49° |
| May | 67° | 42° | 3.1" | 0 | 12 | 0 | 46° – 60° |
| June | 76° | 52° | 3.2" | 0 | 10 | 0 | 60° – 70° |
| July | 81° | 57° | 2.9" | 0 | 10 | 0 | 62° – 73° |
| August | 79° | 56° | 3.2" | 0 | 10 | 0 | 62° – 72° |
| September | 71° | 49° | 3.8" | 0 | 11 | 0 | 54° – 65° |
| October | 57° | 39° | 4.3" | 0.7" | 15 | 0 | 43° – 55° |
| November | 44° | 30° | 3.0" | 10.0" | 15 | 7 | 30° – 44° |
| December | 33° | 21° | 2.6" | 35.4" | 16 | 21 | 19° – 36° |
| Year | 55° | 35° | 34.8" | 122.2" | 149 | 110 |
“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 South Arm
South Arm gets 35 inches of rain and melted snow a year. October is the wettest month and February the driest. Rain or snow falls on about 149 days a year. Snow covers the ground about 110 days of the year.
About 131 frost-free days a year
In half of years the last 32° night comes by May 23 and the first one by October 2. That leaves about 131 frost-free days for gardens, shorter than 94% of U.S. towns.
Heating and cooling a home in South Arm
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In South Arm, 94% of that work is heating and 6% 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.
South Arm and its neighbors
South Arm borders 4 towns with climate data. January nights across them vary by 2.0°. Wilson has both the coldest January nights (13°) and the hottest July afternoons (80°). South Arm’s January low is 14° and its July high 81°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How South Arm 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 South Arm averaged 1.8° warmer than the 1900s. The biggest change is in February (+3.2°). The shift is larger than in 86% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at South Arm’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 7° to 32°. August is the most reliable, staying within 9°.
Common questions about South Arm’s climate
What is the coldest month in South Arm?
February, with a typical high of 30° and a low of 13°.
What is the hottest month in South Arm?
July, with a typical high of 81° and a low of 57°. About 12 days a year reach 90°.
How much snow does South Arm get?
About 122 inches in a normal winter, most of it in January.
When is the first frost in South Arm?
In half of years the first 32° night comes by October 2, and the last spring frost by May 23.
What is the rainiest month in South Arm?
October, with 4.3 inches of rain and melted snow. The year totals 35 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for South Arm itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at East Jordan, MI (2 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.