Sumy Temperature by Month

Sumy in Sumy Oblast, Ukraine sees significant seasonal temperature differences, with daytime highs between -1°C (30°F) in January and 27°C (81°F) in July, averaging 13°C (55°F) annually. Explore the full monthly breakdown below.

With significant temperature fluctuations, Sumy enjoys distinct seasons year-round. Nighttime lows range from 16°C (61°F) in July to -7°C (19°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Sumy by month:

The minimum temperature is often recorded between 4 AM and 6 AM, while the highest temperature is usually reached at 3 PM, when the sun's heating effect is strongest.

The chart below shows the average temperature throughout the year:

Sumy's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:

Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Sumy, January is the coolest month, with average highs of -1°C (30°F) and humidity around 85%, considered very high. In July, the warmest month, temperatures average 27°C (81°F) with 72% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Sumy this rarely lasts long on the ground.

For more on Sumy's weather, including monthly rainfall, sunshine hours, and humidity, visit our Sumy climate page.