Omsk sits on the flat West Siberian Plain at the confluence of the Irtysh and Om rivers, deep in the Russian interior at approximately 54.99°N, 73.37°E. Its extreme continental position gives it a humid continental climate (Köppen Dfb) — with warm summers and long, bitterly cold winters — and one of the widest annual temperature ranges in Russia.

Summer, from June to August, is warm and short, with July the warmest month — average highs around 25–26°C — and hot spells that can exceed 35°C. It is the wettest season, when thunderstorms bring most of the year's modest rainfall, and the long Siberian days are bright and often sunny.

Winter, from November to March, is long and bitterly cold, with January the coldest month — average highs around -13°C and lows near -20°C, and cold snaps below -40°C. The dry Siberian high brings clear, brilliantly cold days; snowfall is light but lies frozen for five months across the open plain, blown into drifts by the wind.

Omsk is dry, receiving only around 400–440 mm of precipitation a year, with a clear summer maximum from thunderstorms; the winter is very dry, as the frigid Siberian air holds almost no moisture, though what snow falls lies for months. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Omsk endures one of the widest temperature ranges of any large Russian city, swinging from below -40°C in deep winter to above 35°C in summer — a spread of over 75°C. The flat West Siberian Plain gives no shelter from either the Arctic air of winter or the hot steppe winds of summer.

To follow any single measurement in Omsk more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.