Sumy, Sumy Weather by Month and Climate Averages

How much rain does Sumy get?

Sumy gets 597 mm of precipitation in an average year, spread over about 151 days with measurable rain. That is more rainy days than 67% of Russia.

July is the wettest month, with 74 mm. April is the driest, with 37 mm. December has the most rainy days, about 18.

The longest dry spell in the last five years lasted 22 days, to October 6, 2024.

Sumy weather by month

Sumy weather in January

In January, Sumy averages a high of -3°C and a low of -8°C. It gets 45 mm of precipitation over about 18 rainy days. The sun is out about 13% of daylight hours. The January record high is 9°C (2023) and the record low is -33°C (1987).

Sumy weather in February

In February, Sumy averages a high of -2°C and a low of -8°C. It gets 40 mm of precipitation over about 15 rainy days. The sun is out about 19% of daylight hours. The February record high is 12°C (1990) and the record low is -34°C (1985).

Sumy weather in March

In March, Sumy averages a high of 4°C and a low of -3°C. It gets 42 mm of precipitation over about 14 rainy days. The sun is out about 34% of daylight hours. The March record high is 21°C (2020) and the record low is -26°C (1987).

Sumy weather in April

In April, Sumy averages a high of 13°C and a low of 3°C. It gets 37 mm of precipitation over about 11 rainy days. The sun is out about 33% of daylight hours. The April record high is 28°C (2024) and the record low is -9°C (2004).

Sumy weather in May

In May, Sumy averages a high of 21°C and a low of 9°C. It gets 60 mm of precipitation over about 12 rainy days. The sun is out about 43% of daylight hours. The May record high is 33°C (2007) and the record low is -3°C (1999). May is one of the most comfortable months to visit.

Sumy weather in June

In June, Sumy averages a high of 24°C and a low of 13°C. It gets 63 mm of precipitation over about 12 rainy days. The sun is out about 48% of daylight hours. The June record high is 39°C (1999) and the record low is 2°C (1977). June is one of the most comfortable months to visit.

Sumy weather in July

In July, Sumy averages a high of 26°C and a low of 15°C. It gets 74 mm of precipitation over about 11 rainy days. The sun is out about 57% of daylight hours. The July record high is 37°C (2024) and the record low is 6°C (2009).

Sumy weather in August

In August, Sumy averages a high of 26°C and a low of 13°C. It gets 39 mm of precipitation over about 8 rainy days. The sun is out about 55% of daylight hours. The August record high is 39°C (2010) and the record low is 2°C (1976). August is one of the most comfortable months to visit.

Sumy weather in September

In September, Sumy averages a high of 19°C and a low of 9°C. It gets 56 mm of precipitation over about 10 rainy days. The sun is out about 50% of daylight hours. The September record high is 33°C (2015) and the record low is -4°C (1986). September is one of the most comfortable months to visit.

Sumy weather in October

In October, Sumy averages a high of 11°C and a low of 3°C. It gets 53 mm of precipitation over about 11 rainy days. The sun is out about 34% of daylight hours. The October record high is 28°C (1999) and the record low is -13°C (1976).

Sumy weather in November

In November, Sumy averages a high of 3°C and a low of -2°C. It gets 41 mm of precipitation over about 13 rainy days. The sun is out about 14% of daylight hours. The November record high is 18°C (2013) and the record low is -24°C (1998).

Sumy weather in December

In December, Sumy averages a high of -2°C and a low of -7°C. It gets 47 mm of precipitation over about 18 rainy days. The sun is out about 12% of daylight hours. The December record high is 10°C (2008) and the record low is -31°C (1997).

Sunshine, humidity and wind in Sumy

July is the sunniest month in Sumy, with sunshine about 57% of daylight hours. December is the cloudiest, at 12%. Over the year the sun shines about 34% of daylight hours. Sumy is sunnier than 59% of Russia.

Humidity peaks in December at 88% and is lowest in May at 59%.

Sumy has about 6 days a year above 32°C. Sumy is hotter than 76% of Russia.

First and last freeze in Sumy

The first fall freeze in Sumy typically comes around October 6, and the last spring freeze around April 25. That leaves a frost-free growing season of about 164 days.

Sumy weather records

The hottest temperature on record at the Sumy station is 39°C, on August 8, 2010. The coldest is -34°C, on February 10, 1985.

The wettest day on record brought 100 mm of rain, on July 14, 2020.

41 all-time records have been set at the station since 1970.

The annual mean temperature has changed by +0.4°C per decade since 1970.

The best time to visit Sumy

The most comfortable time to visit is typically May to June and August to September, when daytime highs sit near 22°C.

Winter (December–February) is cold, with average highs around -2°C and lows near -8°C.

Spring (March–May) is chilly, with average highs around 12°C and lows near 3°C.

Summer (June–August) is warm, with average highs around 25°C and lows near 14°C.

Autumn (September–November) is chilly, with average highs around 11°C and lows near 3°C.

Sumy climate questions

How much rain does Sumy get?

Sumy gets 597 mm of precipitation in an average year, over about 151 rainy days.

What is the wettest month in Sumy?

July is the wettest month in Sumy, with 74 mm. April is the driest, with 37 mm.

How many rainy days does Sumy have a year?

Sumy has about 151 days with measurable rain in an average year. December has the most, about 18.

What is the hottest month in Sumy?

July is the warmest month in Sumy, with an average high of 26°C.

What is the coldest month in Sumy?

January is the coldest month in Sumy, with an average low of -8°C.

What is the record high temperature in Sumy?

The record high at the Sumy station is 39°C, set on August 8, 2010. The record low is -34°C, on February 10, 1985.

What is the sunniest month in Sumy?

July is the sunniest month in Sumy, with sunshine about 57% of daylight hours. December is the cloudiest.

When is the first frost in Sumy?

The first fall freeze in Sumy typically comes around October 6. The last spring freeze is around April 25.

What is the best time to visit Sumy?

The most comfortable time to visit is typically May to June and August to September, when daytime highs sit near 22°C.