South Lyon, MI climate
South Lyon has chilly, snowy winters and pleasant summers. A typical July afternoon reaches 83°, a January night drops to 16°, and about 61 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in South Lyon feels like
Winter
Spring
Summer
Fall
South Lyon 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 | 31° | 16° | 2.1" | 18.3" | 18 | 21 | 14° – 33° |
| February | 34° | 17° | 1.7" | 15.3" | 14 | 17 | 11° – 35° |
| March | 45° | 25° | 2.2" | 8.3" | 14 | 7 | 26° – 49° |
| April | 58° | 36° | 3.1" | 2.6" | 14 | 1 | 40° – 52° |
| May | 70° | 47° | 3.7" | 0 | 15 | 0 | 50° – 64° |
| June | 79° | 56° | 3.5" | 0 | 12 | 0 | 63° – 71° |
| July | 83° | 60° | 3.4" | 0 | 12 | 0 | 66° – 77° |
| August | 80° | 59° | 3.3" | 0 | 11 | 0 | 64° – 74° |
| September | 74° | 51° | 3.0" | 0 | 11 | 0 | 56° – 67° |
| October | 61° | 40° | 2.9" | 0.1" | 13 | 0 | 47° – 57° |
| November | 47° | 31° | 2.5" | 4.1" | 14 | 2 | 32° – 46° |
| December | 35° | 22° | 2.1" | 12.7" | 17 | 12 | 17° – 39° |
| Year | 58° | 38° | 33.4" | 61.4" | 166 | 59 |
“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 Lyon
South Lyon gets 33 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 166 days a year. Snow covers the ground about 59 days of the year.
About 157 frost-free days a year
In half of years the last 32° night comes by May 6 and the first one by October 12. That leaves about 157 frost-free days for gardens, shorter than 74% of U.S. towns.
Heating and cooling a home in South Lyon
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In South Lyon, 92% of that work is heating and 8% 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 Lyon and its neighbors
South Lyon borders 2 towns with climate data. January nights across them vary by 0.2°. Lyon has the coldest January nights (16°) and Green Oak the hottest July afternoons (83°). South Lyon’s January low is 16° and its July high 83°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How South Lyon 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 Lyon averaged 1.8° warmer than the 1900s. The biggest change is in December (+3.0°). The shift is larger than in 87% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at South Lyon’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 11° to 35°. June is the most reliable, staying within 9°.
Common questions about South Lyon’s climate
What is the coldest month in South Lyon?
January, with a typical high of 31° and a low of 16°.
What is the hottest month in South Lyon?
July, with a typical high of 83° and a low of 60°. About 7 days a year reach 90°.
How much snow does South Lyon get?
About 61 inches in a normal winter, most of it in January.
When is the first frost in South Lyon?
In half of years the first 32° night comes by October 12, and the last spring frost by May 6.
What is the rainiest month in South Lyon?
May, with 3.7 inches of rain and melted snow. The year totals 33 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for South Lyon itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Ann Arbor U Of Mich, MI (11 mi, snow) and Milford Gm Proving Ground, MI (8 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.