October Weather in Irkutsk, Russian Federation

Last updated: August 27, 2025

October in Irkutsk, Russian Federation, showcases a diverse range of weather conditions, making it an intriguing time for visitors and locals alike. *With maximum temperatures reaching a pleasant 22°C (71°F), the early part of the month can feel quite mild. However, temperatures take a dip as the month progresses, averaging around 3°C (37°F) and hitting a brisk minimum of -8°C (18°F). *Precipitation levels stand at 25 mm (1.0 in), spread over approximately six days, contributing to a humidity level of 84%. This combination of cool temperatures and occasional rain creates an atmospheric backdrop, perfect for enjoying the autumn landscape of this beautiful Siberian city.

October Temperature in Irkutsk

In October, Irkutsk experiences a notable transition as the warmth of early autumn gives way to the chill of approaching winter. With temperatures ranging from a minimum of -8°C (18°F) to a maximum of 22°C (71°F), the average temperature settles around 3°C (37°F). This month serves as a bridge, showcasing a sharp contrast: while the beginnings of the month may still offer mild days, the latter half dips into cooler spells, hinting at the harsher months ahead. The crisp air, punctuated by the fading foliage, encapsulates both the beauty and briskness of autumn in Siberia, inviting both contemplation and preparation for the cold that lies just ahead.

October Weather in Irkutsk: Daily Temperature Highs, Lows, and Averages

The chart illustrates October temperature patterns in Irkutsk, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Irkutsk, October typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec-232239506166635137192
Data source: Temperature data for Irkutsk generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

October Precipitation in Irkutsk

In October, Irkutsk experiences a noticeable shift in precipitation, with 25 mm (1.0 in) of rain spread over approximately 6 days. This amount marks a decline compared to the wetter summer months, where July and August saw significant rainfall with peaks of 96 mm and 88 mm, respectively. After the lush growth of early fall, the city transitions into a drier phase as the year winds down. Interestingly, October's precipitation serves as a prelude to November's return to lower levels, dropping to 13 mm (0.5 in) over just 4 days. This pattern highlights October as a month of change, bridging the gap between the vibrant summer rains and the crisp approaching winter.

October Precipitation Trends in Irkutsk

The chart displays monthly precipitation patterns in Irkutsk, with values for each month alongside October’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how October’s conditions compare to those of other months. In Irkutsk, October typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec121116204847968875251319
Data source: Precipitation data for October generated using information from the Copernicus Climate Change Service.
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October Humidity in Irkutsk

In October, Irkutsk experiences a humidity level of 84%, consistent with the increased moisture seen in the preceding month of September. This phenomenon signifies a noticeable trend as the autumn season sets in, with humidity levels generally rising from the drier summer months of June and July, which boast lower averages of 64% and 71%, respectively. As the city transitions from warmer temperatures to the chillier months ahead, the humidity tends to climb back towards the 90% mark typical in late autumn and early winter. The gradual increase in moisture content illustrates how Irkutsk prepares for the onset of winter, with only slight fluctuations in humidity from October to November.

October Average Humidity in Irkutsk

This chart illustrates the average monthly humidity levels in Irkutsk, with October’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In October, average humidity in Irkutsk is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec94%90%81%73%67%64%71%73%84%84%90%96%
Data source: Humidity data for October generated using information from the Copernicus Climate Change Service.

October UV Index in Irkutsk

As October rolls into Irkutsk, the UV Index experiences a gentle dip to 3, indicating a moderate level of exposure. During this month, sunbathers should be mindful, with a recommended burn time of 30 minutes. This decrease follows a summer peak, where the Index soared to 8 in both June and July, demanding vigilant sun protection as burn times dropped to just 15 minutes. As the seasons transition into fall, the UV Index gradually recedes, reflecting the diminishing strength of the sun. While outdoor enthusiasts can enjoy the crisp autumn air, it’s essential to stay aware of UV levels to protect your skin. For more comprehensive insights, check out the full details at Irkutsk UV Index.

Maximum UV Index Levels in Irkutsk for October

The chart shows the monthly maximum UV Index (UVI) for Irkutsk in October, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In October, the maximum UV index in Irkutsk typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Irkutsk October UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

October Sunshine in Irkutsk

As October arrives in Irkutsk, the city experiences a gentle decline in sunshine, boasting 280 hours of bright days. This month marks a transition, dipping from the sun-drenched heights of summer, where hours peaked at 376 in June, to the cooler days of winter ahead. The steady decrease in daylight hours reveals a clear seasonal pattern: from the vibrant brightness of late spring, peaking in June and July, daylight begins its gradual retreat. Nonetheless, October's sunny moments still provide a warm embrace, allowing residents and visitors alike to savor the beautiful autumn landscape before the chill of winter sets in.

Monthly Sunshine Duration in Irkutsk: October Highlighted

The October sunshine duration represents the total number of hours Irkutsk experiences direct sunlight during the month of October, excluding cloudy or obstructed periods. This chart compares the sunshine duration of October with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec166h247h310h333h358h376h372h342h295h280h230h191h
Data source: Irkutsk October Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Irkutsk During October

In Irkutsk, October marks a notable shift in weather patterns, with the likelihood of sunny days peaking at 53%—its highest point of the year. This increase contrasts sharply with the winter months, where sunshine chances plummet to a mere 17% in January. As autumn unfolds, the sun begins to break through more consistently, outpacing the often grey skies of earlier fall months like September, which holds steady at 40%. This upward trend in sunshine during October not only hints at the lingering warmth of autumn but also invites outdoor exploration before the onset of harsher winter weather. Overall, for those looking to soak up some rays before winter's grip takes hold, October in Irkutsk offers a promising escape into sunnier days.

Percentage of Sunny Days in October in Irkutsk

The chart illustrates the percentage of sunny days in Irkutsk throughout the year, with October highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Irkutsk experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec17%29%48%40%29%39%39%34%40%53%31%37%
Data source: Irkutsk October chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Irkutsk in October

As the seasons change in Irkutsk, October brings a noticeable shift in daylight, with approximately 10 hours of sunshine illuminating the days. Following the bright, extended days of summer—where sunlight stretches for up to 16 hours in June and July—October marks the transition towards the shorter, gloomier days of winter. After basking in the warmth of 15 hours in May and 14 hours in August, locals now experience a dip in daylight, leading into November’s mere 8 hours. This gradual decrease highlights the rhythmic dance of the seasons, reminding the residents of Irkutsk to cherish the lingering daylight before winter's early nights take hold.

Average Daylight Hours in Irkutsk for October

The chart illustrates the variation in daylight duration in Irkutsk throughout the year, with October highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 16m9h 53m11h 53m13h 56m15h 44m16h 41m16h 11m14h 35m12h 37m10h 35m8h 45m7h 46m
Data source: Irkutsk daylight hours, calculated by summing the hours between sunrise and sunset for each day.

October Winds in Irkutsk

As October descends upon Irkutsk, the wind carries a palpable shift in the atmosphere, with an average speed of 2.3 m/s (5 mph), marking a drop from the slightly brisker September breezes. This month typically signals the transition into colder weather, with the gentle gusts reminiscent of the fading warmth of autumn. The trend reveals a noticeable decrease in wind speed compared to the spring months, peaking in May, where it reached 3.2 m/s (7 mph). As winter approaches, the overall activity of the wind begins to settle, echoing nature's preparation for the chill of November and December. The rhythmic ebb and flow of these October winds in Irkutsk create a serene backdrop, perfect for reflecting on the season’s changing landscape.

Average October Wind Speed in Irkutsk

The chart displays monthly wind speed patterns in Irkutsk, with values for each month shown alongside October's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how October's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.62.72.93.22.92.32.72.82.3 m/s2.52.2
Data source: Irkutsk October wind data, generated using information from the Copernicus Climate Change Service.

How October Weather in Irkutsk Compares to Other Months

Weather in Irkutsk varies notably across the year, with each month offering distinct climate conditions. This page compares October’s weather to other months in Irkutsk, focusing on differences in temperature, rainfall, humidity, and UV levels.

In October, the weather in Irkutsk presents a significant range, with temperatures varying from a chilly -8°C (18°F) at night to a comfortable 22°C (71°F) during the day, averaging around 3°C (37°F). With 25 mm (1.0 in) of precipitation over six days, the humidity hovers at a moderate 84%. In contrast, January brings a harsh winter chill, with temperatures plunging to a severe low of -41°C (-41°F) and averaging -19°C (-1°F), peaking at a mere -5°C (24°F). Precipitation decreases to 12 mm (0.5 in) over four days, but humidity rises to a high of 94%. This stark weather contrast vividly illustrates the transition from autumn's crispness to the biting cold of mid-winter. For more details, you can check Irkutsk weather in January.

In comparing the weather of October and February, we can see marked differences in temperature and precipitation. October experiences a more moderate temperature range, with a minimum of -8°C (18°F), an average of 3°C (37°F), and a maximum of 22°C (71°F). The humidity is moderately high at 84%, and the precipitation is relatively light at 25 mm over 6 days. In contrast, February is significantly colder, with temperatures plummeting to a minimum of -40°C (-39°F) and an average of -16°C (3°F), while only peaking at 5°C (41°F). Humidity in February remains high at 90%, but the precipitation is much lower, totaling 11 mm over just 4 days. For a more detailed look at February weather in Irkutsk, visit Irkutsk weather in February.

When comparing the weather in October and March, it’s evident that October brings a milder climate, with average temperatures around 3°C (37°F) and maximums reaching up to 22°C (71°F), while March presents much colder conditions, averaging -5°C (23°F) and dipping to a chilling minimum of -30°C (-22°F). Precipitation is slightly higher in October at 25 mm (1.0 in) over around six days, compared to March’s 16 mm (0.6 in) over four days. Additionally, October experiences higher humidity levels at 84%, while March maintains a slightly lower humidity of 81%. For a more detailed look at the weather during this time, check out Irkutsk weather in March.

October and April present intriguing contrasts in weather despite their proximity in the calendar year. In October, temperatures range from a chilly minimum of -8°C (18°F) to a mild maximum of 22°C (71°F), with an average temperature of around 3°C (37°F). The month experiences a higher humidity level of 84% and a slight increase in precipitation, totaling 25 mm (1.0 in) over six days. Conversely, April sees slightly cooler conditions, with minimum temperatures dropping to -11°C (13°F) and maximums climbing to 28°C (82°F), but it boasts a higher average temperature of 4°C (39°F). With a total precipitation of 19 mm (0.8 in) over the same six days, April enjoys a lower humidity of 73%. For more details, please check this link: Irkutsk weather in April.

When comparing the weather in October and May, notable differences emerge. October in Irkutsk tends to be chillier, with average temperatures around 3°C (37°F) and a maximum of 22°C (71°F), while May experiences a milder climate, averaging 10°C (50°F) and reaching highs of 31°C (89°F). Precipitation also differs, with October receiving 25 mm (1.0 in) over 6 days and May experiencing greater rainfall of 48 mm (1.9 in) over 11 days. However, October is generally more humid, boasting 84% humidity compared to May's 67%. For more details on May's climate, check out Irkutsk weather in May.

October and June present stark contrasts in weather patterns. In October, temperatures can drop to a minimum of -8°C (18°F), with an average of 3°C (37°F) and a maximum of 22°C (71°F). The month sees around 25 mm (1.0 in) of precipitation over approximately 6 days, coupled with a high humidity of 84%. In contrast, June offers a much warmer climate, with temperatures ranging from a minimum of 2°C (37°F) to a pleasant average of 16°C (61°F), peaking at 33°C (92°F). Precipitation in June is higher at 47 mm (1.8 in), occurring over about 10 days, but the humidity is lower at 64%. For more details on the weather in June, check out Irkutsk weather in June.

In comparing the weather of October and July, a stark contrast emerges in terms of temperature and precipitation. July boasts a much warmer climate, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 32°C (90°F), making it an ideal time for outdoor activities. In contrast, October experiences cooler temperatures, averaging around 3°C (37°F), with nighttime lows dropping to -8°C (18°F). Additionally, July is significantly wetter than October, receiving 96 mm (3.8 in) of rain across 12 days, whereas October sees only 25 mm (1.0 in) of rainfall over just 6 days. The humidity levels are also noteworthy; July has a comfortable 71% humidity compared to the higher 84% in October. For a deeper look into Irkutsk's July conditions, you can check Irkutsk weather in July.

In comparing the weather between October and August, it’s clear that October is significantly cooler, with average temperatures around 3°C (37°F), peaking at a maximum of 22°C (71°F), while August enjoys much warmer conditions with an average of 17°C (63°F) and highs reaching 30°C (86°F). Precipitation levels also differ considerably; October sees 25 mm (1.0 in) of rain over approximately 6 days, whereas August experiences much heavier rainfall at 88 mm (3.5 in) over 12 days. Additionally, humidity is higher in October at 84%, compared to 73% in August, contributing to a sharper chill in the air as the month progresses. For more insights on the climate in August, you can visit Irkutsk weather in August.

October and September in Irkutsk exhibit a notable shift in weather patterns as autumn progresses. September tends to be milder, with average temperatures ranging from a minimum of -1°C (31°F) to a maximum of 26°C (79°F), while October sees a drop in average temperatures, with a minimum of -8°C (18°F) and a maximum of 22°C (71°F). Precipitation is more significant in September, totaling 75 mm (2.9 in) over 10 days compared to October's 25 mm (1.0 in) spread across just 6 days. Interestingly, both months share the same level of humidity at 84%, which contributes to the crisp feeling of October as summer gives way to deeper autumnal chill. For a closer look at September's weather specifics, you can refer to Irkutsk weather in September.

October typically experiences a wider temperature range, with minimum temperatures around -8°C (18°F) and maximums reaching up to 22°C (71°F), resulting in an average of 3°C (37°F). In contrast, November sees a significant drop in temperatures, with minimums plunging to -28°C (-18°F) and an average of -7°C (20°F), peaking at a maximum of just 10°C (50°F). While October receives 25 mm (1.0 in) of precipitation over approximately 6 days, November is drier with only 13 mm (0.5 in) across about 4 days, albeit with higher humidity levels of 90% compared to October's 84%. For more detailed insights, you can refer to Irkutsk weather in November.

October and December in Irkutsk present stark contrasts in weather. October experiences a wider temperature range with minimums dipping to -8°C (18°F) and maximums reaching a mild 22°C (71°F), while average temperatures settle around 3°C (37°F). The month sees moderate precipitation of 25 mm (1.0 in) over about 6 days, accompanied by a relatively high humidity of 84%. In contrast, December brings a deep chill, with minimum temperatures plummeting to a frigid -39°C (-38°F) and average conditions lingering around -17°C (2°F). Precipitation decreases slightly to 19 mm (0.7 in) over 5 days, but humidity rises to a high of 96%, enhancing the cold. For more details, you can check out Irkutsk weather in December.

Compare Irkutsk's Climate with Cities Worldwide

Conclusion: What to Expect From October Weather in Irkutsk

As October unfolds in Irkutsk, the transformation in weather becomes quite pronounced, contrasting sharply with the milder months of late summer. The days feature a mix of temperate highs and briskly cool lows, with a noticeable chill creeping in as winter approaches. While precipitation remains modest, the increasing humidity adds to that crisp, invigorating air, setting a distinctive tone for the month. The dynamic shifts in temperature, with an average around 3°C, mark a clear departure from the warmer days of September. For those interested in a broader understanding of Irkutsk's climatic patterns, explore Irkutsk Climate.