Sumy climate
Sumy (Ukraine) has a warm-summer humid continental climate (Köppen Dfb). The average temperature over the year is 7 °C45 °F, and about 614 mm24 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Sumy climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | −524 | −1112 | −818 | 491.9 | 30 |
| Feb | −327 | −1013 | −720 | 401.6 | 28 |
| Mar | 439 | −523 | −131 | 461.8 | 27 |
| Apr | 1356 | 236 | 846 | 391.5 | 10 |
| May | 2169 | 949 | 1559 | 662.6 | 0 |
| Jun | 2475 | 1356 | 1966 | 682.7 | 0 |
| Jul | 2780 | 1660 | 2170 | 732.9 | 0 |
| Aug | 2780 | 1558 | 2169 | 401.6 | 0 |
| Sep | 2069 | 948 | 1558 | 451.8 | 0 |
| Oct | 1253 | 236 | 745 | 522.0 | 9 |
| Nov | 439 | −228 | 133 | 451.8 | 21 |
| Dec | −228 | −818 | −523 | 512.0 | 28 |
| Year | 2780 | −1112 | 745 | 61424 | 154 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 96% | 85% | 0.9 | 8:24 |
| Feb | 95% | 84% | 1.8 | 9:56 |
| Mar | 87% | 74% | 3.1 | 11:43 |
| Apr | 76% | 64% | 4.3 | 13:45 |
| May | 73% | 58% | 5.7 | 15:30 |
| Jun | 71% | 58% | 6.3 | 16:30 |
| Jul | 68% | 57% | 6.0 | 16:05 |
| Aug | 62% | 52% | 5.2 | 14:32 |
| Sep | 67% | 59% | 3.5 | 12:32 |
| Oct | 79% | 69% | 2.0 | 10:35 |
| Nov | 89% | 80% | 0.9 | 8:50 |
| Dec | 94% | 85% | 0.6 | 7:57 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Sumy is like
The warmest month is July, with an average high of 27 °C80 °F and a low of 16 °C60 °F. The coldest is January, when highs average −5 °C24 °F and lows −11 °C12 °F. Seasons are strongly marked: the warmest month is on average 29.2 °C52.5 °F warmer than the coldest.
Annual precipitation is moderate at about 614 mm24 in. Rain is spread fairly evenly through the year. The wettest month is July (73 mm2.9 in), the driest is April (39 mm1.5 in).
Relative humidity ranges from 62% in August to 96% in January. The clearest skies (lowest average cloud amount, 52%) are typical of August. Average wind speed near the ground ranges from 8 km/h (5 mph) in July to 14 km/h (8 mph) in February. Daylight lasts from about 7.9 hours in December to 16.5 hours in June.
A lasting snow cover is typical in November–March. In those months the average snow depth in the reanalysis exceeds 10 cm. It is deepest in February, at about 27 cm.
Best time to visit Sumy
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May–September. Average highs then reach 20 °C69 °F to 27 °C80 °F. Precipitation is 40 mm1.6 in to 73 mm2.9 in per month.
The most challenging month is January, which is cold, with average highs of −5 °C24 °F.
Comfort score: months are ranked by how close they come to an ideal. That means an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Sumy
- Winter (December–February) — highs −524 to −2 °C28 °F, lows −1112 to −8 °C18 °F, about 47 mm1.8 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots.
- Spring (March–May) — highs 439 to 21 °C69 °F, lows −523 to 9 °C49 °F, about 50 mm2.0 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 2475 to 27 °C80 °F, lows 1356 to 16 °C60 °F, about 61 mm2.4 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Autumn (September–November) — highs 439 to 20 °C69 °F, lows −228 to 9 °C48 °F, about 47 mm1.9 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
How Sumy compares
The nearest larger place is Belgorod, about 130 km to the east. Compared with it, Sumy has practically the same average temperature. It receives a similar amount of precipitation. The difference is largest in August (0.8 °C1.5 °F cooler).
World Climates covers 41 places in Ukraine. By annual mean temperature, Sumy is the 41st warmest of them. By annual precipitation, it is the 12th wettest. See all of them on the Ukraine climate page.
Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Belgorod (Russia, Dfa), Kursk (Russia, Dfb) and Staryy Oskol (Russia, Dfb).
Nearby places
- Climate in Belgorod 130 km · 7 °C45 °F · 601 mm24 in
- Climate in Kursk 132 km · 7 °C44 °F · 654 mm26 in
- Climate in Kharkiv 146 km · 8 °C47 °F · 584 mm23 in
- Climate in Poltava 149 km · 8 °C47 °F · 580 mm23 in
- Climate in Staryy Oskol 217 km · 7 °C45 °F · 622 mm24 in
- Climate in Kremenchuk 229 km · 10 °C49 °F · 550 mm22 in
- Climate in Orël 244 km · 6 °C42 °F · 683 mm27 in
- Climate in Chernihiv 253 km · 8 °C46 °F · 627 mm25 in
Frequently asked questions
What is the warmest month in Sumy?
July is the warmest month in Sumy. Its average high is 27 °C (80 °F) and its average low is 16 °C (60 °F).
What is the coldest month in Sumy?
January is the coldest month. Its average high is -5 °C (24 °F) and its average low is -11 °C (12 °F).
When does it rain the most in Sumy?
July is the wettest month with about 73 mm (2.9 in) of precipitation. April is the driest with about 39 mm (1.5 in).
What is the best time to visit Sumy?
Judging by long-term averages, the most comfortable months are May–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station. So they can differ from airport records. The gaps are largest on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.