Chatham, Michigan climate: Normal weather by month, frost dates and records
Chatham's normal year runs from 9°F January nights to 76°F July afternoons, with 37.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.8°C, January lows of −13°C, July highs of 24°C, 939 mm of precipitation a year.
- NOAA stationChatham (1 mi SE)
- Station IDUSW00054810
- Location46.33°N 86.92°W
- Elevation875 ft (267 m)
- Population215
On October 22, the normal high in Chatham is 50°F and the normal low 33°F, and the chance of measurable rain or snow is 54%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Chatham.
- Jan 24° 9°
- Feb 26° 7°
- Mar 35° 16°
- Apr 47° 27°
- May 61° 38°
- Jun 71° 48°
- Jul 76° 52°
- Aug 75° 52°
- Sep 67° 46°
- Oct 53° 35°
- Nov 40° 25°
- Dec 29° 16°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Chatham each month?
July is the warmest month, with normal highs of 76°F; January the coldest, with normal lows of 9°F. The most precipitation falls in October (4.42 in), the least in February (1.91 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 24°F | 9°F | 16.2°F | 2.54 | 20 | <1 | 30 | 9 h |
| February | 26°F | 7°F | 16.8°F | 1.91 | 17 | <1 | 28 | 10 h 20 min |
| March | 35°F | 16°F | 25.5°F | 2.07 | 14 | <1 | 28 | 11 h 50 min |
| April | 47°F | 27°F | 36.9°F | 2.79 | 12 | <1 | 23 | 13 h 30 min |
| May | 61°F | 38°F | 49.7°F | 3.39 | 14 | <1 | 9 | 15 h |
| June | 71°F | 48°F | 59.0°F | 3.52 | 13 | <1 | 1 | 15 h 50 min |
| July | 76°F | 52°F | 63.9°F | 3.33 | 12 | 1 | <1 | 15 h 30 min |
| August | 75°F | 52°F | 63.2°F | 2.89 | 10 | <1 | <1 | 14 h 10 min |
| September | 67°F | 46°F | 56.3°F | 4.04 | 12 | <1 | 2 | 12 h 40 min |
| October | 53°F | 35°F | 44.2°F | 4.42 | 17 | <1 | 13 | 11 h |
| November | 40°F | 25°F | 32.6°F | 3.37 | 15 | <1 | 23 | 9 h 30 min |
| December | 29°F | 16°F | 22.5°F | 2.70 | 19 | <1 | 30 | 8 h 40 min |
| Year (annual) | 50°F | 31°F | 40.6°F | 36.97 | 173 | 2 | 186 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −5°C | −13°C | −8.8°C | 65 mm |
| February | −3°C | −14°C | −8.4°C | 49 mm |
| March | 2°C | −9°C | −3.6°C | 53 mm |
| April | 8°C | −3°C | 2.7°C | 71 mm |
| May | 16°C | 3°C | 9.8°C | 86 mm |
| June | 21°C | 9°C | 15.0°C | 89 mm |
| July | 24°C | 11°C | 17.7°C | 85 mm |
| August | 24°C | 11°C | 17.3°C | 73 mm |
| September | 19°C | 8°C | 13.5°C | 103 mm |
| October | 12°C | 2°C | 6.8°C | 112 mm |
| November | 4°C | −4°C | 0.3°C | 86 mm |
| December | −2°C | −9°C | −5.3°C | 69 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Chatham's own co-op station Chatham Experiment Farm 2 does: 164 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00054810; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Chatham?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, August has the fewest days with rain (10).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00054810.
When is the last frost in Chatham?
In Chatham, the last spring frost (32°F) comes after May 27 in half of years and after June 12 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 9 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 271 year in 10 after June 12; 9 in 10 after May 11
- First autumn frost, half of years before
- September 281 year in 10 before September 9; 9 in 10 before October 12
NOAA puts the median frost-free season at 124 days, and the season without a hard freeze (28°F) at 150 days.
A hard freeze (28°F) comes after May 12 in half of springs and before October 11 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Chatham in zone 5a in ZIP code 49825, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Chatham's NOAA station is in zone 4b: the coldest night of a typical year reaches −20°F (16 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Michigan · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00054810; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Chatham?
In a normal year in Chatham, 2 days a year reach 90°F, 186 nights fall to 32°F or colder and 173 days bring measurable precipitation.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 186a normal year
- Days that stay below freezing
- 88high of 32°F or less
- Days with 0.01 inch of precipitation
- 173a normal year
The highest temperature in this station's record (since 2004) is 97°F, on July 13, 2026; the lowest is −32°F, on February 28, 2014.
The wettest calendar year on that record is 2017, with 49.31 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00054810; records: ACIS (NOAA Regional Climate Centers), station USW00054810. Records use complete months only; a month missing more than three days is left out.
How sunny is Chatham?
Over a year 67% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Chatham, 3.4 kWh per square metre a day. July is the sunniest month (77%) and December the cloudiest (48%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 49% | 1.1 |
| February | 55% | 1.9 |
| March | 63% | 3.2 |
| April | 66% | 4.4 |
| May | 69% | 5.4 |
| June | 72% | 5.9 |
| July | 77% | 6.0 |
| August | 75% | 5.0 |
| September | 70% | 3.7 |
| October | 60% | 2.2 |
| November | 52% | 1.3 |
| December | 48% | 0.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Chatham need?
A normal year in Chatham brings 9,031 heating degree days, 68% more than the median U.S. place (5,373), and 163 cooling degree days, 82% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,510 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,514 | 0 |
| February | 1,349 | 0 |
| March | 1,225 | 0 |
| April | 842 | 0 |
| May | 476 | 4 |
| June | 205 | 25 |
| July | 97 | 65 |
| August | 104 | 50 |
| September | 280 | 19 |
| October | 647 | 1 |
| November | 974 | 0 |
| December | 1,317 | 0 |
| Year (annual) | 9,031 | 163 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00054810. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Chatham been warmer than normal lately?
2025 averaged 41.3°F, 0.7°F above the 1991-2020 normal of 40.6°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 43.1°F | +2.5°F | 32.32 |
| 2022 | 40.2°F | −0.4°F | 42.36 |
| 2023 | 42.5°F | +1.9°F | 40.30 |
| 2024 | 44.4°F | +3.8°F | 41.66 |
| 2025 | 41.3°F | +0.7°F | 41.43 |
Source: observed years: ACIS, station USW00054810. A year counts only with all twelve months complete.
How does Chatham's climate compare?
Chatham is warmer than 5 of the other 139 places with their own NOAA record in Michigan, and wetter than 103. Across the 7,247 U.S. stations with normals, its annual mean of 40.6°F is warmer than 7%.
In the Köppen classification computed from these normals, Chatham is Dfb: continental, no dry season, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
What do Chatham's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Chatham. This page uses Chatham (1 mi SE); the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Chatham Experiment Farm 2 USC00201486 | 1 mi N | 870 ft | 41.4°F | 8°F | 78°F | 35.1 | 164 | May 30 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Chatham's climate
What is the coldest month in Chatham?
January, with a normal high of 24°F and a normal low of 9°F. The warmest is July (76°F by day, 52°F at night).
Does it snow in Chatham?
Yes. NOAA publishes no 1991-2020 snowfall normal for Chatham's NOAA station; Chatham's own co-op station Chatham Experiment Farm 2 records 164 inches of snow in a normal year.
What is the rainiest month in Chatham?
October, with 4.42 in of precipitation in a normal year; the driest is February with 1.91 in.
What plant hardiness zone is Chatham in?
The USDA's 2023 map puts Chatham in zone 5a in ZIP code 49825, the nearest ZIP area. By the same method at Chatham's NOAA station, the coldest night of a typical year reaches −20°F (16 years, 1991-2020): zone 4b.
How late can frost come in Chatham?
In half of years the last 32°F night comes after May 27; in one year in ten it comes after June 12. Waiting until June 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Michigan climateThe statewide normals and every place in the state
- Munising, MI14 miles from this station, 40.9°F a year
- Munsing Lakeshore, MI14 miles from this station, 42.3°F a year
- Ki Sawyer Wastewater Treatment Plant, MI22 miles from this station, 41.9°F a year
- Marquette, MI26 miles from this station, 42.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made