Watertown climate — normals and trends
Watertown (United States) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 6.2 °C and it receives 673 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 (21.8 °C on average) and the coldest is January (-11.3 °C). Rainfall peaks in June.
Watertown averages 161 frost days, 19 hot days (≥ 30 °C) and 93 rainy days per year.
Watertown has warmed by +1.9 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.
The number of frost days there went from about 167 to 155 per year over the period.
The hottest day of the period reached 39.3 °C (on 31 July 1988) and the coldest -37.4 °C (on 2 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
WatertownSouth Dakota
- coords
- 44.90°, -97.12°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
6.2°C
Average daily high
11.2°C
Average daily low
1.3°C
Annual rainfall
673mm
Sunshine / day
9.2h
Mean relative humidity
72%
Average peak wind
24.2km/h
Seasonal range
33.1°C
Frost days (< 0 °C)
161 d/yr
Hot days (≥ 30 °C)
19 d/yr
Rainy days (≥ 1 mm)
93 d/yr
Annual snowfall
93.0 cm
Average feels-like high
8.0 °C
Average feels-like low
-2.7 °C
Average peak gust
42.5 km/h
Tropical nights (≥ 20 °C)
10 d/yr
Solar radiation
15.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.24 · 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
39.3 °C
31 July 1988
Coldest day
-37.4 °C
2 February 1996
Wettest day
110 mm
16 August 2017
Windiest day
76.3 km/h
9 November 1977
Strongest gust
107.3 km/h
20 April 1955
Hottest feels-like
42.8 °C
30 July 1955
Coldest feels-like
-44.9 °C
2 February 1996
Snowiest day
33.2 cm
9 November 1977
Sunniest day
15.0 h
30 May 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 | -4.6 °C | +2.2 °C | 5 mm | -16 mm |
| Feb | -4.3 °C | +0.1 °C | 12 mm | -10 mm |
| Mar | 9.0 °C | +6.9 °C | 33 mm | -11 mm |
| Apr | 12.6 °C | +1.1 °C | 84 mm | +14 mm |
| May | 20.2 °C | +1.4 °C | 106 mm | +19 mm |
| Jun | 24.5 °C | +0.4 °C | 173 mm | +70 mm |
| Jul | 26.7 °C | -0.5 °C | 121 mm | +43 mm |
| Aug | 24.9 °C | -1.2 °C | 119 mm | +40 mm |
| Sep | 23.8 °C | +2.6 °C | 50 mm | -11 mm |
| Oct | 16.6 °C | +2.5 °C | 26 mm | -24 mm |
| Nov | 6.5 °C | +2.5 °C | 27 mm | -6 mm |
| Dec | -1.2 °C | +2.4 °C | 21 mm | -3 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 Watertown?
Watertown has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 6.2 °C and it receives 673 mm of precipitation per year.
What is the hottest day ever recorded in Watertown?
The hottest day measured in Watertown between 1940 and 2025 was 31 July 1988, reaching 39.3 °C.
What is the coldest day in Watertown?
The coldest day measured in Watertown between 1940 and 2025 was 2 February 1996, at -37.4 °C.
Does it snow in Watertown?
Yes. Watertown gets on average 93.0 cm of snow per year and has around 161 frost days.
Has the climate of Watertown warmed?
Yes: Watertown warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Watertown?
The wettest day measured in Watertown between 1940 and 2025 was 16 August 2017, with 110 mm of rain in 24 hours.
What was the windiest day in Watertown?
The windiest day measured in Watertown between 1940 and 2025 was 9 November 1977, with winds reaching 76.3 km/h.
What is the warmest month in Watertown?
The warmest month in Watertown is July (21.8 °C on average); the coldest is January (-11.3 °C).
How much does it rain in Watertown?
Watertown receives on average 673 mm of precipitation per year, spread over about 93 rainy days.
Is it sunny in Watertown?
Watertown gets on average 9.2 hours of sunshine per day, roughly 3,358 hours per year over 1940-2025.
What is the biggest single-day snowfall in Watertown?
The heaviest 24-hour snowfall measured in Watertown between 1940 and 2025 was 9 November 1977, with 33.2 cm.
Are there tropical nights in Watertown?
Yes: Watertown has on average 10 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Watertown?
In Watertown, between 1940 and 2025, the highest apparent temperature reached 42.8 °C on 30 July 1955, and the lowest was -44.9 °C on 2 February 1996.
Compare Watertown with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Watertown