September Weather in Altay, Mongolia

Last updated: August 28, 2025

September in Altay, Mongolia is marked by a striking temperature range, with maximums peaking at 29°C (84°F) and dipping to a chilly minimum of -13°C (9°F). The average temperature settles around a crisp 8°C (47°F), providing a refreshing contrast to the summer heat. This month also welcomes a modest precipitation total of 29 mm (1.2 in), spread over approximately 6 days, contributing to the lush post-summer landscape. With relative humidity levels hovering around 71%, the atmosphere is often imbued with a cool, refreshing quality, making September a unique time to experience the rugged beauty of Altay.

September Temperature in Altay

In September, Altay, Mongolia begins to transition from the warm embrace of summer to the crispness of autumn. With minimum temperatures dipping to -13°C (9°F) and an average hovering around 8°C (47°F), the month marks a noticeable shift from the previous warmer months. Daytime highs can still reach a pleasant 29°C (84°F), allowing for some lingering warmth, but the chill is undeniable as the nights draw in. This gradual drop in temperature reflects a broader trend of cooling that characterizes the region's early fall season, presenting a perfect blend of mild days and brisk evenings. As September unfolds, the landscape transforms, inviting nature lovers to appreciate the stunning hues of autumn.

September Weather in Altay: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Altay, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Altay, September 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-16-712344859635847283-14
Data source: Temperature data for Altay 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.

September Precipitation in Altay

In September, Altay, Mongolia experiences a notable shift in its precipitation dynamics, receiving 29 mm (1.2 in) of rain over the course of 6 days. This marks a decline from the summer peak, reflecting a transition into autumn. Despite the decrease from the 79 mm recorded in August, September's rainfall is still significant compared to earlier months, indicating a lingering moisture influence as the seasons change. The advent of this precipitation serves to rejuvenate the landscape, preparing it for the drier months ahead. As the year progresses, the rainfall pattern underscores a clear seasonal rhythm, where the peak summer months give way to the more moderate conditions of fall, offering a glimpse of nature's cyclical beauty in the region.

September Precipitation Trends in Altay

The chart displays monthly precipitation patterns in Altay, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Altay, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec561019284368792920127
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Altay

September in Altay, Mongolia experiences a moderate humidity level of 71%, reflecting a gradual transition as summer ebbs away. Following the peak of humidity during the warmer months, from 65% in July to 67% in August, September's readings signify a slight increase, setting the stage for the more humid autumn months ahead. As temperatures begin to drop, humidity levels rise again, hinting at the onset of a typically wetter climate that will intensify through October, hitting 80%. This pattern underscores the shift in Altay's weather dynamics, where the interplay between temperature and humidity continues to shape the region's distinct seasonal charm.

September Average Humidity in Altay

This chart illustrates the average monthly humidity levels in Altay, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Altay is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec95%90%84%76%63%60%65%67%71%80%92%96%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Altay

In September, Altay, Mongolia experiences a UV Index of 6, placing it in the high exposure category with a burn time of approximately 25 minutes. This marks a noticeable decline from the intense peaks of the summer months, where the UV Index reached as high as 9, indicating very high exposure. As the seasons transition into autumn, sun exposure becomes slightly more forgiving, yet still warrants caution. With the UV Index beginning to decrease, September offers a reminder that even in the fall, UV radiation can pose risks. Awareness of sun safety remains essential, particularly for outdoor activities. For more detailed information, check out the Altay UV Index.

Maximum UV Index Levels in Altay for September

The chart shows the monthly maximum UV Index (UVI) for Altay in September, 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 September, the maximum UV index in Altay typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235799986421
Data source: Altay September 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.

September Sunshine in Altay

As September unfolds in Altay, Mongolia, the sun continues to warm the landscape with a generous 332 hours of daylight, although it marks a decline from the vibrant summer months. Following a peak of 392 hours in July, the light begins to wane, hinting at the transition into autumn. This drop is consistent with the seasonal trend, where daylight gradually reduces from the highs of summer to the drier, shorter days of winter. Nevertheless, September still showcases a significant amount of sunshine, allowing the stunning beauty of the Altay Mountains to bask in the glow of early autumn. The shift in light not only highlights the changing colors of the season but also invites outdoor adventures before the chill of October sets in with only 312 hours of sun.

Monthly Sunshine Duration in Altay: September Highlighted

The September sunshine duration represents the total number of hours Altay experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec195h265h338h356h389h390h392h363h332h312h251h240h
Data source: Altay September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Altay During September

September in Altay, Mongolia, marks a notable shift in the likelihood of sunny weather, boasting a remarkable 62% chance of sun. This increase positions September as one of the sunniest months of the year, following the summer's peak but contrasting with the cloudy days of August, which dips to 40%. As autumn approaches, the trend continues to improve with October seeing an even higher 66% likelihood of sunshine, hinting at a cheerful transition into fall. The data indicates a seasonal pattern where summer's sunfulness gives way to golden autumn days, making September an ideal time for outdoor exploration under clear blue skies.

Percentage of Sunny Days in September in Altay

The chart illustrates the percentage of sunny days in Altay throughout the year, with September 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 Altay experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec40%47%50%50%46%52%42%40%62%66%58%54%
Data source: Altay September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Altay in September

As September unfolds in Altay, Mongolia, the days begin to gently shorten, offering about 12 hours of daylight. This month marks a transition from the peak summer radiance, where June boasts a generous 16 hours of sunlight, to the more subdued daylight hours of October and November. The progression throughout the year reveals a rhythmic ebb and flow: after long summer days in May and June, the sunlight begins to recede, with September providing a balanced mix of warmth and gradual twilight. This captivating shift not only heralds the approach of autumn but also enhances the scenic beauty of the landscape, inviting both reflection and exploration before the shorter days of winter settle in.

Average Daylight Hours in Altay for September

The chart illustrates the variation in daylight duration in Altay throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 38m10h 5m11h 54m13h 46m15h 23m16h 13m15h 47m14h 21m12h 34m10h 43m9h 4m8h 11m
Data source: Altay daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Altay

In September, the winds in Altay, Mongolia, continue to whisper softly through the landscape at an average speed of 2.4 m/s (5 mph), reflecting a pattern of relatively gentle breezes that have graced the region throughout the summer months. After a gradual climb from 1.9 m/s in January to the peak of 3.4 m/s in May, the winds began to settle, suggesting a transition into the more tranquil autumn days. This consistency in wind speed indicates a prevailing calmness as the landscape prepares for the upcoming seasonal changes. Notably, September's breezes mirror the gentle gusts of both August and July, fostering a serene atmosphere that invites exploration and appreciation of Mongolia's breathtaking natural beauty.

Average September Wind Speed in Altay

The chart displays monthly wind speed patterns in Altay, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec1.92.12.32.83.42.52.12.42.4 m/s2.02.22.0
Data source: Altay September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Altay Compares to Other Months

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

September and January present strikingly different weather patterns. September offers a wide temperature range, with minimums of -13°C (9°F) and maximums reaching up to 29°C (84°F), allowing for relatively mild days with an average temperature of 8°C (47°F). In contrast, January plunges into extreme cold, where temperatures can drop to a chilling -46°C (-50°F) at night, with an average of -27°C (-16°F) and a maximum of only -8°C (18°F). Additionally, September experiences more precipitation (29 mm over 6 days) compared to January's meager 5 mm over just 1 day, highlighting the stark difference in humidity levels, which is significantly higher in January at 95%. For more insights into January weather in Altay, check out Altay weather in January.

September and February present stark contrasts in weather conditions. In September, temperatures range from a chilly -13°C (9°F) to a warm 29°C (84°F), with an average of 8°C (47°F). The month sees about 29 mm (1.2 in) of precipitation over approximately 6 days and a humidity level of 71%. In sharp contrast, February experiences much harsher conditions, with temperatures plunging to a minimum of -42°C (-43°F) and an average of -22°C (-7°F), capping at just 1°C (33°F). Precipitation during this month is minimal at 6 mm (0.3 in) across only 2 days, coupled with a higher humidity level of 90%. For a deeper dive into the weather patterns in February, you can check out Altay weather in February.

In comparing the weather between September and March, it's clear that September offers much milder temperatures, with an average of 8°C (47°F) and a maximum of 29°C (84°F), while March is significantly colder, averaging -11°C (12°F) and reaching a minimum of -35°C (-31°F). Precipitation is more frequent in September, totaling 29 mm (1.2 in) over six days, whereas March sees only 10 mm (0.4 in) over three days. Additionally, March experiences higher humidity at 84%, compared to September's 71%. For more detailed insights, you can check Altay weather in March.

September and April present a stark contrast in weather conditions. While September boasts a more moderate average temperature of 8°C (47°F) with highs reaching up to 29°C (84°F), April experiences significantly colder temperatures averaging just 1°C (34°F) and a maximum of 24°C (75°F). Notably, April can dip to a chilling minimum of -23°C (-10°F). Precipitation is slightly heavier in September, totaling 29 mm (1.2 in) over 6 days compared to April's 19 mm (0.7 in) over 5 days. Additionally, humidity levels are higher in April at 76% compared to September's 71%. For detailed insights into April weather, refer to Altay weather in April.

In comparing the weather of September and May, we find that both months exhibit a range of temperatures, but with slightly different characteristics. September experiences a broader temperature range, with a minimum of -13°C (9°F) and a maximum of 29°C (84°F), and an average temperature of 8°C (47°F). In contrast, May's temperatures are slightly milder, featuring a minimum of -10°C (15°F) and a maximum of 28°C (82°F), with an average of 9°C (48°F).

Precipitation is relatively similar between the two months, with September receiving 29 mm (1.2 in) over 6 days, while May sees slightly less precipitation at 28 mm (1.1 in) spread across 8 days. Additionally, September has a higher humidity level at 71%, compared to May's 63%. For more detailed information about weather in May, you can refer to Altay weather in May.

In comparing the weather of September and June, significant differences emerge in both temperature and precipitation. September tends to be cooler, with an average temperature of 8°C (47°F), ranging from a minimum of -13°C (9°F) to a maximum of 29°C (84°F), alongside a humidity level of 71%. In contrast, June enjoys milder conditions, boasting an average temperature of 15°C (59°F) and a broader temperature range between -2°C (29°F) and 31°C (88°F) with lower humidity at 60%. Precipitation is slightly higher in June, totaling 43 mm (1.7 in) over 9 days compared to September's 29 mm (1.2 in) over 6 days. For more detailed insights about June weather, check the following link: Altay weather in June.

September and July exhibit distinct weather patterns that reflect the transition between summer and autumn. In September, temperatures can dip to a minimum of -13°C (9°F) and reach a maximum of 29°C (84°F), with an average of 8°C (47°F). The month experiences around 29 mm (1.2 inches) of precipitation over approximately 6 days, accompanied by a humidity level of 71%. In contrast, July boasts milder temperatures, with a minimum of 3°C (38°F), an average of 17°C (63°F), and a maximum of 31°C (87°F). July is considerably wetter, receiving about 68 mm (2.7 inches) of rainfall over 12 days, while humidity is slightly lower at 65%. For a deeper look at July's climate, you can read more about the Altay weather in July.

In September, the weather in Altay exhibits a broader temperature range compared to August, with minimums dropping to -13°C (9°F) and maximums reaching 29°C (84°F). The average temperature for September is cooler at 8°C (47°F), significantly lower than August's average of 15°C (58°F). Interestingly, while September has lower overall precipitation at 29 mm (1.2 in) over 6 days, August experiences more rainfall, totaling 79 mm (3.1 in) across 11 days. Humidity remains relatively stable between the two months, with September at 71% and August slightly lower at 67%. For a closer look at August conditions, visit Altay weather in August.

September and October present a noticeable shift in weather conditions. In September, temperatures range from a minimum of -13°C (9°F) to a maximum of 29°C (84°F), with an average of 8°C (47°F) and relatively low precipitation of 29 mm (1.2 in) over 6 days. The humidity sits at 71%, making the air feel moderately comfortable.

In contrast, October sees a drop in temperatures, with minimums plunging to -23°C (-9°F) and an average temperature of -2°C (28°F). The maximum temperature is significantly lower at 18°C (65°F). Precipitation decreases slightly to 20 mm (0.8 in), also falling over 6 days, but humidity rises to 80%, contributing to a sharper chill in the air. For a detailed look at October weather specifics, you can check Altay weather in October.

September and November present strikingly different weather conditions. In September, temperatures can range from a chilly minimum of -13°C (9°F) to a warm maximum of 29°C (84°F), with an average of 8°C (47°F). The month sees moderate precipitation of 29 mm (1.2 in) over 6 days, accompanied by a humidity level of 71%. In contrast, November brings a much harsher climate, where temperatures plummet to a minimum of -39°C (-38°F) and an average of -16°C (4°F), with a maximum of only 4°C (40°F). Precipitation decreases significantly to just 12 mm (0.5 in) over 4 days, while humidity rises to 92%. The change in weather from September to November highlights the transition into winter's grip. For more detailed insights, you can refer to Altay weather in November.

In September, temperatures range from a chilly -13°C (9°F) at night to a warm 29°C (84°F) during the day, with an average of 8°C (47°F). The month experiences moderate precipitation at 29 mm (1.2 in) over approximately 6 days, accompanied by a humidity level of 71%. In stark contrast, December brings much harsher conditions, with temperatures plunging to a minimum of -45°C (-48°F) and an average of -26°C (-14°F), peaking at only -4°C (25°F). Precipitation is significantly lower at 7 mm (0.3 in) across just 2 days, and humidity is much higher at 96%. For more details on December weather conditions, you can visit Altay weather in December.

Compare Altay's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Altay

As September arrives in Altay, the weather transitions into a unique blend of warmth and chill, marking a significant shift from the hot summer months. Daytime temperatures can soar up to 29°C (84°F), yet the nights can plunge to a chilly -13°C (9°F). This stark contrast creates a fascinating dynamic that distinguishes September from the more predictable climes of summer. With an average temperature of 8°C (47°F) and a humidity level at 71%, the air feels crisp and invigorating. Although rainfall is modest, with only 29 mm (1.2 in) over about six days, the month often heralds the onset of autumn. For those interested in exploring the broader patterns of Altay’s climate, be sure to check out Altay Climate.