Average Weather in Irkutsk Russia
In Irkutsk, the summers are comfortable, the winters are frigid and dry, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from -12°F to 75°F and is rarely below -30°F or above 85°F.
Based on the tourism score, the best time of year to visit Irkutsk for warm-weather activities is from late June to mid August.
The warm season lasts for 3.9 months, from May 15 to September 11, with an average daily high temperature above 61°F. The hottest day of the year is July 14, with an average high of 75°F and low of 54°F.
The cold season lasts for 3.1 months, from November 22 to February 25, with an average daily high temperature below 20°F. The coldest day of the year is January 17, with an average low of -12°F and high of 6°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
In Irkutsk, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Irkutsk begins around April 21 and lasts for 6.0 months, ending around October 20. On August 21, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 54% of the time, and overcast or mostly cloudy 46% of the time.
The cloudier part of the year begins around October 20 and lasts for 6.0 months, ending around April 21. On November 29, the cloudiest day of the year, the sky is overcast or mostly cloudy 66% of the time, and clear, mostly clear, or partly cloudy 34% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Irkutsk varies significantly throughout the year.
The wetter season lasts 4.5 months, from May 8 to September 22, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 35% on August 4.
The drier season lasts 7.5 months, from September 22 to May 8. The smallest chance of a wet day is 1% on February 14.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Irkutsk changes throughout the year.
Rain alone is the most common for 6.8 months, from April 3 to October 28. The highest chance of a day with rain alone is 35% on August 4.
Snow alone is the most common for 5.2 months, from October 28 to April 3. The highest chance of a day with snow alone is 4% on November 24.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Irkutsk experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 5.5 months, from April 25 to October 10, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 30, with an average total accumulation of 3.0 inches.
The rainless period of the year lasts for 6.5 months, from October 10 to April 25. The least rain falls around January 2, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Irkutsk does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Irkutsk varies extremely over the course of the year. In 2019, the shortest day is December 22, with 7 hours, 41 minutes of daylight; the longest day is June 21, with 16 hours, 48 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 4:40 AM on June 18, and the latest sunrise is 4 hours, 32 minutes later at 9:12 AM on December 31. The earliest sunset is at 4:49 PM on December 13, and the latest sunset is 4 hours, 39 minutes later at 9:28 PM on June 25.
Daylight saving time (DST) is not observed in Irkutsk during 2019.
Sunrise & Sunset with Twilight
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Irkutsk, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 1% of 1% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Irkutsk experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 2.7 months, from March 16 to June 7, with average wind speeds of more than 6.8 miles per hour. The windiest day of the year is April 19, with an average hourly wind speed of 8.1 miles per hour.
The calmer time of year lasts for 9.3 months, from June 7 to March 16. The calmest day of the year is July 19, with an average hourly wind speed of 5.4 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Irkutsk varies throughout the year.
The wind is most often from the north for 3.6 months, from March 22 to July 11, with a peak percentage of 38% on April 21. The wind is most often from the west for 8.4 months, from July 11 to March 22, with a peak percentage of 39% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Irkutsk throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Irkutsk for general outdoor tourist activities is from late June to mid August, with a peak score in the last week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Irkutsk for hot-weather activities is for the entire month of July, with a peak score in the third week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Irkutsk typically lasts for 3.7 months (113 days), from around May 25 to around September 15, rarely starting before May 9 or after June 9, and rarely ending before August 31 or after September 30.
Time Spent in Various Temperature Bands and the Growing Season
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
Based on growing degree days alone, the first spring blooms in Irkutsk should appear around May 16, only rarely appearing before May 7 or after May 25.
Growing Degree Days
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.5 months, from April 30 to August 13, with an average daily incident shortwave energy per square meter above 5.4 kWh. The brightest day of the year is June 19, with an average of 6.5 kWh.
The darker period of the year lasts for 3.5 months, from October 27 to February 13, with an average daily incident shortwave energy per square meter below 2.0 kWh. The darkest day of the year is December 22, with an average of 0.8 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Irkutsk are 52.298 deg latitude, 104.296 deg longitude, and 1,437 ft elevation.
The topography within 2 miles of Irkutsk contains only modest variations in elevation, with a maximum elevation change of 394 feet and an average elevation above sea level of 1,448 feet. Within 10 miles contains only modest variations in elevation (666 feet). Within 50 miles contains significant variations in elevation (3,609 feet).
The area within 2 miles of Irkutsk is covered by artificial surfaces (94%), within 10 miles by trees (53%) and artificial surfaces (19%), and within 50 miles by trees (75%) and water (13%).
This report illustrates the typical weather in Irkutsk, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Irkutsk.
For each station, the records are corrected for the elevation difference between that station and Irkutsk according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Irkutsk is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Irkutsk and a given station.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.