Bay City climate — normals and trends
Bay City (United States) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 8.4 °C and it receives 829 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (21.7 °C on average) and the coldest is January (-5.6 °C). Rainfall peaks in May.
Bay City averages 135 frost days, 19 hot days (≥ 30 °C) and 118 rainy days per year.
Bay City has warmed by +2.1 °C between 1940 and 2025, or +0.25 °C per decade. This trend is statistically significant.
The number of frost days there went from about 147 to 123 per year over the period.
The hottest day of the period reached 39.2 °C (on 7 July 1988) and the coldest -31.4 °C (on 3 February 1996).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Bay CityMichigan
- coords
- 43.59°, -83.89°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.4°C
Average daily high
13.3°C
Average daily low
3.7°C
Annual rainfall
829mm
Sunshine / day
8.8h
Mean relative humidity
72%
Average peak wind
19.5km/h
Seasonal range
27.3°C
Frost days (< 0 °C)
135 d/yr
Hot days (≥ 30 °C)
19 d/yr
Rainy days (≥ 1 mm)
118 d/yr
Annual snowfall
89.6 cm
Average feels-like high
10.9 °C
Average feels-like low
0.5 °C
Average peak gust
38.6 km/h
Tropical nights (≥ 20 °C)
13 d/yr
Solar radiation
14.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.3 °C per decade · r² = 0.41 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.2 °C
7 July 1988
Coldest day
-31.4 °C
3 February 1996
Wettest day
71 mm
24 June 1994
Windiest day
60.8 km/h
30 April 1984
Strongest gust
114.5 km/h
30 April 1984
Hottest feels-like
42.8 °C
14 July 1995
Coldest feels-like
-37.1 °C
3 February 1996
Snowiest day
31.7 cm
26 January 1978
Sunniest day
15.0 h
2 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | -2.3 °C | -0.4 °C | 17 mm | -33 mm |
| Feb | -1.1 °C | -0.6 °C | 38 mm | -7 mm |
| Mar | 10.9 °C | +5.6 °C | 87 mm | +24 mm |
| Apr | 14.5 °C | +1.5 °C | 65 mm | -17 mm |
| May | 18.0 °C | -1.5 °C | 95 mm | +9 mm |
| Jun | 26.7 °C | +1.8 °C | 105 mm | +20 mm |
| Jul | 28.6 °C | +1.4 °C | 66 mm | -12 mm |
| Aug | 26.6 °C | +0.6 °C | 54 mm | -26 mm |
| Sep | 24.2 °C | +2.2 °C | 43 mm | -31 mm |
| Oct | 17.8 °C | +2.5 °C | 85 mm | +18 mm |
| Nov | 7.3 °C | -0.1 °C | 34 mm | -31 mm |
| Dec | -0.5 °C | -1.3 °C | 70 mm | +15 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Bay City?
Bay City has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 8.4 °C and it receives 829 mm of precipitation per year.
What is the hottest day ever recorded in Bay City?
The hottest day measured in Bay City between 1940 and 2025 was 7 July 1988, reaching 39.2 °C.
What is the coldest day in Bay City?
The coldest day measured in Bay City between 1940 and 2025 was 3 February 1996, at -31.4 °C.
Does it snow in Bay City?
Yes. Bay City gets on average 89.6 cm of snow per year and has around 135 frost days.
Has the climate of Bay City warmed?
Yes: Bay City warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Bay City?
The wettest day measured in Bay City between 1940 and 2025 was 24 June 1994, with 71 mm of rain in 24 hours.
What was the windiest day in Bay City?
The windiest day measured in Bay City between 1940 and 2025 was 30 April 1984, with winds reaching 60.8 km/h.
What is the warmest month in Bay City?
The warmest month in Bay City is July (21.7 °C on average); the coldest is January (-5.6 °C).
How much does it rain in Bay City?
Bay City receives on average 829 mm of precipitation per year, spread over about 118 rainy days.
Is it sunny in Bay City?
Bay City gets on average 8.8 hours of sunshine per day, roughly 3,212 hours per year over 1940-2025.
What is the biggest single-day snowfall in Bay City?
The heaviest 24-hour snowfall measured in Bay City between 1940 and 2025 was 26 January 1978, with 31.7 cm.
Are there tropical nights in Bay City?
Yes: Bay City has on average 13 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Bay City?
In Bay City, between 1940 and 2025, the highest apparent temperature reached 42.8 °C on 14 July 1995, and the lowest was -37.1 °C on 3 February 1996.
Compare Bay City with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Bay City