Hamilton climate — normals and trends
Hamilton (United States) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 11.8 °C and it receives 1,043 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 (24.1 °C on average) and the coldest is January (-1.5 °C). Rainfall peaks in May.
Hamilton averages 95 frost days, 34 hot days (≥ 30 °C) and 125 rainy days per year.
Hamilton has warmed by +1.7 °C between 1940 and 2025, or +0.19 °C per decade. This trend is statistically significant.
The number of frost days there went from about 107 to 83 per year over the period.
The hottest day of the period reached 39.2 °C (on 14 July 1954) and the coldest -30.8 °C (on 19 January 1994).
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
HamiltonOhio
- coords
- 39.40°, -84.56°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
11.8°C
Average daily high
16.8°C
Average daily low
7.3°C
Annual rainfall
1,043mm
Sunshine / day
8.7h
Mean relative humidity
69%
Average peak wind
17.0km/h
Seasonal range
25.6°C
Frost days (< 0 °C)
95 d/yr
Hot days (≥ 30 °C)
34 d/yr
Rainy days (≥ 1 mm)
125 d/yr
Annual snowfall
48.1 cm
Average feels-like high
15.3 °C
Average feels-like low
5.0 °C
Average peak gust
37.0 km/h
Tropical nights (≥ 20 °C)
39 d/yr
Solar radiation
14.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.34 · 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
14 July 1954
Coldest day
-30.8 °C
19 January 1994
Wettest day
118 mm
9 March 1964
Windiest day
49.0 km/h
14 September 2008
Strongest gust
113.0 km/h
30 January 2013
Hottest feels-like
42.8 °C
14 July 1995
Coldest feels-like
-36.6 °C
20 January 1985
Snowiest day
23.2 cm
22 March 1968
Sunniest day
14.7 h
11 June 2025
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 | 0.0 °C | -2.6 °C | 49 mm | -32 mm |
| Feb | 5.1 °C | +0.3 °C | 122 mm | +45 mm |
| Mar | 15.4 °C | +4.9 °C | 100 mm | -6 mm |
| Apr | 18.7 °C | +1.6 °C | 153 mm | +46 mm |
| May | 21.3 °C | -1.2 °C | 94 mm | -14 mm |
| Jun | 28.8 °C | +1.6 °C | 147 mm | +53 mm |
| Jul | 30.4 °C | +1.4 °C | 97 mm | +8 mm |
| Aug | 27.5 °C | -0.8 °C | 44 mm | -31 mm |
| Sep | 27.1 °C | +2.2 °C | 53 mm | -13 mm |
| Oct | 19.5 °C | +1.1 °C | 90 mm | +22 mm |
| Nov | 10.8 °C | -0.1 °C | 60 mm | -27 mm |
| Dec | 5.1 °C | +0.3 °C | 68 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 Hamilton?
Hamilton has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 11.8 °C and it receives 1,043 mm of precipitation per year.
What is the hottest day ever recorded in Hamilton?
The hottest day measured in Hamilton between 1940 and 2025 was 14 July 1954, reaching 39.2 °C.
What is the coldest day in Hamilton?
The coldest day measured in Hamilton between 1940 and 2025 was 19 January 1994, at -30.8 °C.
Does it snow in Hamilton?
Yes. Hamilton gets on average 48.1 cm of snow per year and has around 95 frost days.
Has the climate of Hamilton warmed?
Yes: Hamilton warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Hamilton?
The wettest day measured in Hamilton between 1940 and 2025 was 9 March 1964, with 118 mm of rain in 24 hours.
What was the windiest day in Hamilton?
The windiest day measured in Hamilton between 1940 and 2025 was 14 September 2008, with winds reaching 49.0 km/h.
What is the warmest month in Hamilton?
The warmest month in Hamilton is July (24.1 °C on average); the coldest is January (-1.5 °C).
How much does it rain in Hamilton?
Hamilton receives on average 1,043 mm of precipitation per year, spread over about 125 rainy days.
Is it sunny in Hamilton?
Hamilton gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.
What is the biggest single-day snowfall in Hamilton?
The heaviest 24-hour snowfall measured in Hamilton between 1940 and 2025 was 22 March 1968, with 23.2 cm.
Are there tropical nights in Hamilton?
Yes: Hamilton has on average 39 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Hamilton?
In Hamilton, between 1940 and 2025, the highest apparent temperature reached 42.8 °C on 14 July 1995, and the lowest was -36.6 °C on 20 January 1985.
Compare Hamilton with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Hamilton