Flat Rock, MI climate
Flat Rock has chilly, snowy winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 19°, and about 45 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Flat Rock feels like
Winter
Spring
Summer
Fall
Flat Rock 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 | 33° | 19° | 2.3" | 14.0" | 13 | 17 | 16° – 36° |
| February | 36° | 21° | 2.0" | 12.5" | 11 | 14 | 14° – 37° |
| March | 46° | 28° | 2.4" | 6.2" | 11 | 6 | 28° – 50° |
| April | 59° | 38° | 3.3" | 1.5" | 13 | 1 | 42° – 54° |
| May | 70° | 49° | 3.8" | 0 | 13 | 0 | 52° – 66° |
| June | 80° | 59° | 3.4" | 0 | 11 | 0 | 64° – 74° |
| July | 84° | 63° | 3.4" | 0 | 11 | 0 | 69° – 78° |
| August | 82° | 62° | 3.5" | 0 | 10 | 0 | 67° – 76° |
| September | 75° | 55° | 3.1" | 0 | 10 | 0 | 60° – 69° |
| October | 62° | 44° | 2.8" | 0 | 11 | 0 | 49° – 59° |
| November | 49° | 33° | 2.7" | 1.9" | 11 | 2 | 34° – 48° |
| December | 37° | 25° | 2.3" | 8.9" | 13 | 8 | 19° – 41° |
| Year | 59° | 41° | 34.8" | 45.0" | 136 | 47 |
“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 Flat Rock
Flat Rock gets 35 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 136 days a year. Snow covers the ground about 47 days of the year.
About 188 frost-free days a year
In half of years the last 32° night comes by April 20 and the first one by October 27. That leaves about 188 frost-free days for gardens, longer than 62% of U.S. towns.
Heating and cooling a home in Flat Rock
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Flat Rock, 88% of that work is heating and 12% 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.
Flat Rock and its neighbors
Flat Rock borders 6 towns with climate data. January nights across them vary by 1.9°. Huron has both the coldest January nights (18°) and the hottest July afternoons (84°). Flat Rock’s January low is 19° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Flat Rock 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 Flat Rock averaged 1.5° warmer than the 1900s. The biggest change is in December (+2.6°). The shift is larger than in 73% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Flat Rock’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 14° to 37°. September is the most reliable, staying within 9°.
Common questions about Flat Rock’s climate
What is the coldest month in Flat Rock?
January, with a typical high of 33° and a low of 19°.
What is the hottest month in Flat Rock?
July, with a typical high of 84° and a low of 63°. About 13 days a year reach 90°.
How much snow does Flat Rock get?
About 45 inches in a normal winter, most of it in January.
When is the first frost in Flat Rock?
In half of years the first 32° night comes by October 27, and the last spring frost by April 20.
What is the rainiest month in Flat Rock?
May, with 3.8 inches of rain and melted snow. The year totals 35 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Flat Rock itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Detroit Metro Airport, MI (10 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.