Sumy climate — normals and trends
Sumy (Ukraine) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 7.0 °C and it receives 619 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 (19.9 °C on average) and the coldest is January (-6.7 °C). Rainfall peaks in July.
Sumy averages 134 frost days, 9 hot days (≥ 30 °C) and 120 rainy days per year.
Sumy has warmed by +3.2 °C between 1940 and 2025, or +0.37 °C per decade. This trend is statistically significant.
The number of frost days there went from about 154 to 114 per year over the period.
The hottest day of the period reached 38.7 °C (on 8 August 2010) and the coldest -38.1 °C (on 22 January 1942).
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
SumySumy
- coords
- 50.92°, 34.80°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
7.0°C
Average daily high
10.8°C
Average daily low
3.1°C
Annual rainfall
619mm
Sunshine / day
7.3h
Mean relative humidity
76%
Average peak wind
19.5km/h
Seasonal range
26.6°C
Frost days (< 0 °C)
134 d/yr
Hot days (≥ 30 °C)
9 d/yr
Rainy days (≥ 1 mm)
120 d/yr
Annual snowfall
100.5 cm
Average feels-like high
7.8 °C
Average feels-like low
-0.3 °C
Average peak gust
36.0 km/h
Tropical nights (≥ 20 °C)
3 d/yr
Solar radiation
11.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.2 °C
since 1940
+0.4 °C per decade · r² = 0.50 · 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
38.7 °C
8 August 2010
Coldest day
-38.1 °C
22 January 1942
Wettest day
57 mm
14 July 2020
Windiest day
60.7 km/h
11 December 1967
Strongest gust
96.1 km/h
29 November 1974
Hottest feels-like
38.4 °C
16 July 1951
Coldest feels-like
-44.2 °C
22 January 1942
Snowiest day
20.6 cm
27 February 1971
Sunniest day
15.7 h
27 June 1951
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 | 3.0 °C | +7.2 °C | 19 mm | -24 mm |
| Feb | -2.6 °C | +0.4 °C | 14 mm | -25 mm |
| Mar | 10.4 °C | +7.9 °C | 45 mm | +3 mm |
| Apr | 15.8 °C | +3.2 °C | 33 mm | -14 mm |
| May | 19.2 °C | -0.2 °C | 50 mm | -9 mm |
| Jun | 22.5 °C | -0.5 °C | 63 mm | -4 mm |
| Jul | 27.4 °C | +2.7 °C | 78 mm | +4 mm |
| Aug | 24.6 °C | +0.4 °C | 43 mm | -14 mm |
| Sep | 21.0 °C | +2.5 °C | 14 mm | -35 mm |
| Oct | 10.9 °C | 0.0 °C | 105 mm | +58 mm |
| Nov | 8.2 °C | +5.1 °C | 50 mm | +1 mm |
| Dec | 0.8 °C | +2.5 °C | 40 mm | -6 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 Sumy?
Sumy has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 7.0 °C and it receives 619 mm of precipitation per year.
What is the hottest day ever recorded in Sumy?
The hottest day measured in Sumy between 1940 and 2025 was 8 August 2010, reaching 38.7 °C.
What is the coldest day in Sumy?
The coldest day measured in Sumy between 1940 and 2025 was 22 January 1942, at -38.1 °C.
Does it snow in Sumy?
Yes. Sumy gets on average 100.5 cm of snow per year and has around 134 frost days.
Has the climate of Sumy warmed?
Yes: Sumy warmed by +3.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Sumy?
The wettest day measured in Sumy between 1940 and 2025 was 14 July 2020, with 57 mm of rain in 24 hours.
What was the windiest day in Sumy?
The windiest day measured in Sumy between 1940 and 2025 was 11 December 1967, with winds reaching 60.7 km/h.
What is the warmest month in Sumy?
The warmest month in Sumy is July (19.9 °C on average); the coldest is January (-6.7 °C).
How much does it rain in Sumy?
Sumy receives on average 619 mm of precipitation per year, spread over about 120 rainy days.
Is it sunny in Sumy?
Sumy gets on average 7.3 hours of sunshine per day, roughly 2,665 hours per year over 1940-2025.
What is the biggest single-day snowfall in Sumy?
The heaviest 24-hour snowfall measured in Sumy between 1940 and 2025 was 27 February 1971, with 20.6 cm.
Are there tropical nights in Sumy?
Yes: Sumy has on average 3 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Sumy?
In Sumy, between 1940 and 2025, the highest apparent temperature reached 38.4 °C on 16 July 1951, and the lowest was -44.2 °C on 22 January 1942.
Compare Sumy with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Sumy