Sumy, Ukraine climate

Dfb Warm-summer humid continental

Sumy has a strongly seasonal cool-temperate climate (Warm-summer humid continental, Köppen Dfb). The hottest month is July with an average daily high near 80°F, while the coldest is January averaging around 18°F at night. Around 22 inches of precipitation falls each year, peaking in July (3.5 inches) and easing off in November (0.9 inches). At latitude 51°N, day length swings from 7.7 hours in midwinter to 16.3 hours at midsummer.

☀️ Summers

Warm

Highs near 80°F in July.

About 6 days a year above 90 °F

❄️ Winters

Very cold

Lows near 18°F in January.

About 98 freezing nights a year

🌧️ Rain

Moderate rainfall

About 22 in of rain a year.

Wettest in July

⛅ Sky & trend

Often cloudy

Cloudy skies much of the year.

+1.7 °F vs 50 years ago

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Sumy climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	27	29	39	58	70	76	80	78	67	53	39	29
Avg temp (°F)	22	23	32	48	60	66	70	67	58	46	34	25
Avg low (°F)	18	18	26	39	48	56	59	56	47	37	30	21
Precipitation (in)	1.3	1.2	1.4	1.1	2.6	2.5	3.5	1.1	2.5	2.7	0.9	1.5

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°F)	27	29	39	58	70	76
Avg temp (°F)	22	23	32	48	60	66
Avg low (°F)	18	18	26	39	48	56
Precipitation (in)	1.3	1.2	1.4	1.1	2.6	2.5

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	80	78	67	53	39	29
Avg temp (°F)	70	67	58	46	34	25
Avg low (°F)	59	56	47	37	30	21
Precipitation (in)	3.5	1.1	2.5	2.7	0.9	1.5

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	11	10	9	6	6	6	6	4	6	7	8	11
Days with high ≥ 90°F (days)	—	—	—	—	0.1	0.4	2	2	0.2	—	—	—
Days with low ≤ 32°F (days)	19	19	18	5	0.3	—	0.0	—	0.3	6	12	18

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	11	10	9	6	6	6
Days with high ≥ 90°F (days)	—	—	—	—	0.1	0.4
Days with low ≤ 32°F (days)	19	19	18	5	0.3	—

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	6	4	6	7	8	11
Days with high ≥ 90°F (days)	2	2	0.2	—	—	—
Days with low ≤ 32°F (days)	0.0	—	0.3	6	12	18

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	75	75	71	68	62	59	58	55	61	69	75	76
Clear days (≤ 30% cloud)	3	2	4	4	6	5	6	7	6	5	2	4
Partly cloudy days (30–70%)	8	7	8	9	11	13	13	13	10	8	7	6
Cloudy days (≥ 70%)	20	19	19	17	15	12	12	11	14	18	20	22
Relative humidity (%)	96	95	86	75	73	71	68	62	68	79	89	94
Wind speed (mph)	8.3	8.5	8.1	6.8	5.9	5.7	5.3	5.4	6.0	6.4	6.9	7.7

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	75	75	71	68	62	59
Clear days (≤ 30% cloud)	3	2	4	4	6	5
Partly cloudy days (30–70%)	8	7	8	9	11	13
Cloudy days (≥ 70%)	20	19	19	17	15	12
Relative humidity (%)	96	95	86	75	73	71
Wind speed (mph)	8.3	8.5	8.1	6.8	5.9	5.7

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	58	55	61	69	75	76
Clear days (≤ 30% cloud)	6	7	6	5	2	4
Partly cloudy days (30–70%)	13	13	10	8	7	6
Cloudy days (≥ 70%)	12	11	14	18	20	22
Relative humidity (%)	68	62	68	79	89	94
Wind speed (mph)	5.3	5.4	6.0	6.4	6.9	7.7

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 26 years of daily observations at Sumy, a weather station, about 12 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →