Climate Insights for Irkutsk

The climate in Irkutsk is cold. The average annual temperature is 1°C and approximately 426mm of precipitation falls per year. August is the wettest month, receiving around 95mm of rainfall. Irkutsk is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, February, December, when temperatures can drop to -24°C. Snowfall occurs from January to December, with around 63cm accumulating over the season.

Irkutsk has a wide annual temperature range, spanning 48°C from the coldest to warmest months. July is the warmest month, though highs remain moderate at 24°C with a mean of 19°C. January brings the harshest conditions, with lows dropping to -24°C and an average temperature of -19°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between February and March, with a 11°C shift in average temperatures.

Irkutsk is a relatively dry area, receiving approximately 426mm of precipitation annually, which averages out to around 35mm per month. The wettest month is August, averaging 95mm of rainfall. July and September also tend to see above-average precipitation. The driest month is February, with just 7mm. That's 88mm less than August, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Snowfall is a regular feature from January to December, with around 63cm accumulating over the season. November typically sees the most snow at around 10cm.

Irkutsk is mildly breezy, with an average annual wind speed of 14km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is May, averaging 18km/h, though still comfortable for most outdoor activities. The calmest conditions occur in December, with average winds dropping to 11km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 7km/h gap between the calmest and windiest months.

It is currently spring in Irkutsk, which began on March 20, 2026. Irkutsk is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 24°C, while the coldest stretch bottoms out in January near -24°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Irkutsk is during June, July and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 78mm per month. By contrast, January can be quite cold with temperatures dropping to -24°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Irkutsk based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.