Irkutsk climate

Name: Irkutsk
Address: RU

Irkutsk is warmest in July, with average highs of 24 °C, and coldest in January, when nights average -24 °C. August is the wettest month (102 mm) and February the driest (5.5 mm). Figures are 1991–2020 climate normals.

Across a full year Irkutsk averages 456 mm of rain, 37 days above 25 °C and 206 days below freezing.

Russia · population 623,869 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month July 24 °C
Coldest month January -24 °C
Driest month February 6 mm
Wettest month August 102 mm
Least cloud March 56 % cloud
Hottest on record June 36 °C
Coldest on record January -44 °C

What to expectIrkutsk through the year

Irkutsk has a clear annual cycle: average daily highs run from -14 °C in January to 24 °C in July, a swing of 38 °C in mean temperature across the year.

Counted across a normal year, 37 days a year reach 25 °C, 5 of them reach 30 °C, 206 nights drop below freezing. The warmest reading in the 1991–2020 record is 36 °C, in June.

Rain is strongly seasonal. August averages 102 mm against 6 mm in February — 18 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	-14.1 °C	6 mm	60 %
February	-8.6 °C	6 mm	57 %
March	-0.0 °C	11 mm	56 %
April	9.4 °C	22 mm	60 %
May	16.7 °C	39 mm	58 %
June	22.6 °C	68 mm	60 %
July	24.4 °C	96 mm	63 %
August	22.1 °C	102 mm	62 %
September	15.2 °C	61 mm	59 %
October	6.8 °C	23 mm	59 %
November	-3.7 °C	13 mm	71 %
December	-11.7 °C	10 mm	68 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	-14.1 °C	-23.7 °C	-19.1 °C	1.1 °C	-43.9 °C	0	0	31
February	-8.6 °C	-21.0 °C	-14.8 °C	5.1 °C	-40.9 °C	0	0	28
March	-0.0 °C	-12.8 °C	-6.2 °C	16.7 °C	-31.4 °C	0	0	31
April	9.4 °C	-2.6 °C	3.1 °C	26.5 °C	-16.3 °C	0	0	24
May	16.7 °C	3.6 °C	10.2 °C	32.3 °C	-5.5 °C	3	0	6
June	22.6 °C	10.8 °C	16.8 °C	36.3 °C	-1.8 °C	11	2	0
July	24.4 °C	14.0 °C	19.2 °C	34.4 °C	5.4 °C	15	2	0
August	22.1 °C	12.3 °C	17.0 °C	34.8 °C	2.8 °C	8	1	0
September	15.2 °C	5.4 °C	10.1 °C	29.5 °C	-4.8 °C	1	0	2
October	6.8 °C	-2.2 °C	1.9 °C	21.3 °C	-15.6 °C	0	0	23
November	-3.7 °C	-11.6 °C	-7.8 °C	10.1 °C	-32.7 °C	0	0	30
December	-11.7 °C	-20.1 °C	-15.9 °C	2.7 °C	-42.2 °C	0	0	31

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	6 mm	2	8.2 h/day	60 %	73 %	12 km/h
February	6 mm	2	9.9 h/day	57 %	71 %	13 km/h
March	11 mm	3	12 h/day	56 %	66 %	15 km/h
April	22 mm	6	14 h/day	60 %	55 %	18 km/h
May	39 mm	9	16 h/day	58 %	55 %	18 km/h
June	68 mm	11	17 h/day	60 %	64 %	15 km/h
July	96 mm	12	16 h/day	63 %	73 %	13 km/h
August	102 mm	12	15 h/day	62 %	75 %	14 km/h
September	61 mm	10	13 h/day	59 %	75 %	15 km/h
October	23 mm	6	11 h/day	59 %	74 %	15 km/h
November	13 mm	4	8.8 h/day	71 %	76 %	14 km/h
December	10 mm	3	7.7 h/day	68 %	76 %	12 km/h

How Irkutsk compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Irkutsk	24 °C	-24 °C	456 mm	37
Angarsk · Russia	25 °C	-26 °C	393 mm	42
Ulan-Ude · Russia	26 °C	-28 °C	296 mm	46
Bratsk · Russia	21 °C	-22 °C	365 mm	7

Where Irkutsk ranks

Ranking	Position	Value
The driest places in Europe in November	5th of 50	13 mm
The driest places in Europe in December	6th of 50	10 mm
The driest places in Europe in February	6th of 50	5.5 mm
The driest places in Europe in January	6th of 50	5.9 mm
The driest places in Europe in March	6th of 50	11 mm
The driest places in Europe in October	7th of 50	23 mm

Planning a trip? See the best time to visit Irkutsk.

QuestionsCommon questions about Irkutsk’s climate

When is the best time to visit Irkutsk?

That depends on what you want, so the honest answer is a comparison rather than a single month. June, July, August sit closest to 20 °C on average, July is the warmest month and February the driest. The month-by-month table above has the full picture.

How hot does Irkutsk get?

In July, the warmest month, daily highs average 24 °C. About 5 days a year pass 30 °C. The highest value in the 1991–2020 record is 36 °C.

How cold does it get in winter?

Nights average -24 °C in January, the coldest month. A normal year has 206 nights below freezing.

Which month is wettest in Irkutsk?

August, averaging 102 mm over 12 days with rain. The driest month is February with 6 mm. The year as a whole averages 456 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Irkutsk rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 52.296°, 104.291° (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.