Last updated: August 28, 2025
In September, Altai, Mongolia experiences a notable transition in weather as it shifts from the warmth of summer to the cooler embrace of autumn. Daily maximum temperatures can soar to a comfortable 26°C (80°F), while the average temperature settles around a brisk 9°C (49°F). Nights can be quite chilly, with minimum temperatures dipping to -7°C (19°F). This month sees a modest precipitation level of 19 mm (0.8 in) over roughly 4 days, contributing to a humidity level of 59% that enhances the crispness of the air. September in Altai presents a vibrant tapestry of climate changes, making it a captivating time for both adventure and reflection.
In September, Altai, Mongolia, begins to feel the crisp embrace of autumn with temperatures markedly cooling from the summer's heat. The minimum temperature dips to -7°C (19°F), while the average settles around a mild 9°C (49°F), offering a refreshing break from the warmer months. With a maximum temperature reaching 26°C (80°F), there are still warm spells to enjoy, particularly in the early part of the month. This transitional period showcases the beauty of change in Altai, as colorful foliage begins to emerge and the landscape shifts, reminding residents and visitors alike of the approaching winter. Overall, September serves as a gentle reminder that summer is waning, paving the way for the cooler months ahead.
In September, Altai, Mongolia experiences a notable shift in its precipitation patterns, receiving 19 mm (0.8 in) of rain across 4 days. This marks a drop from the more substantial showers of August, where 66 mm (2.6 in) fell over the same number of days. The transition in precipitation signifies the approaching end of the wet season, highlighting a trend of decreasing rainfall as the year progresses toward the colder months. With September's rainfall, the region still benefits from moisture, supporting the lingering warmth of early autumn, while setting the stage for the dryer conditions of October that follow.
In Altai, Mongolia, September marks a notable shift in humidity, rising to 59% after the drier summer months. This slight increase from August’s 54% signals the onset of autumn, as cooler temperatures begin to intertwine with the lingering warmth. The transition is accompanied by a gradual return to the more moisture-laden conditions characteristic of the coming months. As autumn approaches, the humidity will continue to climb, setting the stage for the more humid and cold months ahead, where winter's grip brings humidity levels soaring back up to 96% by December. This cyclical pattern of humidity reflects the region's unique climate, where shifts in season dramatically influence atmospheric conditions.
In September, the UV Index in Altai, Mongolia, registers at 7, placing it in the high exposure category with a burn time of 25 minutes. This marks a shift from the peak levels observed during the summer months, where the UV Index peaked at a consistent 10, signaling a very high risk for unprotected skin. As the autumn season approaches, sunlight intensity begins to wane, yet it's essential to remain cautious. Notably, September's UV levels echo those observed in March, illustrating a seasonal pattern that encourages vigilance at both ends of the year. To stay informed and safe in your outdoor adventures, check the latest updates on the Altai UV Index.
UV Risk Categories
As September unfolds in Altai, Mongolia, the embrace of autumn sunlight begins to weave a tapestry of golden hues across the landscape. With 338 hours of sunshine, September captures the essence of summer's lingering warmth while gracefully transitioning into the cooler months. This represents a slight decline from the blazing summer peak of 398 hours in July, yet remains vibrant as autumn approaches. Notably, the sunshine steadily decreases after August’s 374 hours, reflecting a natural rhythm where daylight begins to wane. Overall, September's ample sunshine serves as a gentle reminder of the lush, bright days gone by, setting the stage for the serene beauty of the fall season ahead.
In September, Altai, Mongolia, experiences a notable increase in sunny weather, with a 77% chance of clear skies. This marks a striking rebound compared to the preceding summer months, where the likelihood of sunshine drops to around 46% in August and continues to decline through July. The shift in September not only highlights the transition toward autumn but also offers a delightful window for outdoor activities, as the chances of enjoying warm, sunny days rise significantly. As temperatures gradually cool, September stands out as a perfect balance between lingering warmth and a beautiful display of autumn hues, making it an ideal time to explore the stunning landscapes of Altai.
As September unfolds in Altai, Mongolia, the daylight duration begins its gentle descent, offering about 12 hours of natural light. This month marks a striking shift from the sun-drenched heights of summer, where June and July basked in 15 hours of daylight. Following the vibrant growth of spring and the lengthy days of summer, September transitions us towards autumn, where the days gradually shorten. With the daylight hours reducing to 10 hours by October, it's clear that nature is preparing for the colder months ahead. This rhythmic change not only defines the beauty of the seasons but also influences the daily lives of those in this breathtaking region.
As the seasons transition in Altai, Mongolia, September brings a gentle breeze with an average wind speed of 3.0 m/s (7 mph). This marks a slight increase from the summer months, where the air was notably calmer, with July and August seeing winds around 2.7 m/s (6 mph) and 2.9 m/s (7 mph) respectively. The gradual uptick in wind velocity signals the arrival of autumn, reminiscent of the crisp, refreshing energy that sweeps across the plains. Notably, the wind speeds peak in May at 4.1 m/s (9 mph), showcasing the spring's lively gusts, before tapering off again as winter approaches. In this dynamic rhythm, September stands as a bridge between the warmth of summer and the chill of approaching cold, offering an invigorating atmosphere perfect for outdoor exploration.
Weather in Altai varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Altai, focusing on differences in temperature, rainfall, humidity, and UV levels.
September offers a much milder climate with temperatures ranging from a minimum of -7°C (19°F) to a pleasant maximum of 26°C (80°F) and an average of 9°C (49°F). The month experiences some rainfall, with 19 mm (0.8 in) of precipitation over four days, and relative humidity at 59%. In stark contrast, January brings severe cold, where temperatures plummet to a minimum of -35°C (-30°F) and barely rise above -2°C (29°F), averaging -17°C (2°F). Precipitation is minimal in January, with only 3 mm (0.1 in) and no recorded rainy days, resulting in extremely high humidity levels at 98%. For more details about January weather, you can check Altai weather in January.
September and February present stark contrasts in weather. In September, temperatures range from a minimum of -7°C (19°F) to a pleasant maximum of 26°C (80°F), with an average of 9°C (49°F). The month sees moderate precipitation of 19 mm (0.8 in) over about four days, accompanied by a humidity level of 59%. In contrast, February plunges into colder territory, where temperatures can drop to as low as -27°C (-17°F) and typically average around -13°C (10°F), peaking at just 6°C (43°F). This month experiences significantly lower precipitation at only 6 mm (0.2 in) over one day, but the humidity rises to a high 94%. For further details on February weather, you can refer to Altai weather in February.
In September, the weather unfolds with a more temperate climate, featuring a minimum temperature of -7°C (19°F) and an average of 9°C (49°F), peaking at a maximum of 26°C (80°F). With only 19 mm (0.8 in) of precipitation over about 4 days, the humidity rests at a moderate 59%. In contrast, March presents a much colder atmosphere, with temperatures dipping to a minimum of -20°C (-4°F) and an average of -4°C (24°F), while only reaching a maximum of 13°C (56°F). The month sees slightly less precipitation, at 10 mm (0.4 in) over 3 days, but the humidity rises significantly to 88%. For more detailed information about March weather in this region, check out Altai weather in March.
In September, the weather is generally milder, with average temperatures ranging from a minimum of -7°C (19°F) to a maximum of 26°C (80°F), resulting in a comfortable average of 9°C (49°F). The month experiences relatively low precipitation, with only 19 mm (0.8 in) spread over 4 days and a humidity level of 59%. In contrast, April is colder, showcasing a minimum temperature of -16°C (4°F) and a maximum of 22°C (72°F), leading to an average temperature of just 3°C (38°F). Though there is slightly less precipitation at 17 mm (0.7 in) over the same number of days, the humidity is notably higher at 74%. For more details on April weather, you can check Altai weather in April.
In September, temperatures tend to be milder, with a minimum of -7°C (19°F) and a maximum reaching up to 26°C (80°F), while the average hovers around 9°C (49°F). The month experiences relatively low precipitation, with only 19 mm (0.8 in) or 4 rainy days and a humidity level of 59%. In contrast, May features cooler temperatures, with a minimum of -11°C (12°F), an average of 10°C (49°F), and a maximum of 24°C (76°F). Interestingly, May also sees 19 mm (0.8 in) of precipitation, but spread over 6 days, resulting in a lower humidity of 50%. For more details on weather in May, you can visit Altai weather in May.
In comparing the weather of September and June, it's clear that June offers warmer conditions, with average temperatures rising to 15°C (60°F) compared to September's cooler average of 9°C (49°F). The maximum temperature in June can reach up to 29°C (84°F), whereas in September, it peaks at 26°C (80°F). Additionally, June experiences slightly more precipitation, with 27 mm (1.1 in) over 8 days, compared to September's 19 mm (0.8 in) over just 4 days. Another notable difference is humidity; June has a lower humidity level of 48%, while September's humidity stands at 59%. For more detailed information, you can check Altai weather in June.
In comparing the weather of September and July, September generally offers cooler temperatures, with a minimum of -7°C (19°F) and an average of 9°C (49°F), while July boasts milder temperatures ranging from a minimum of 4°C (40°F) to an average of 17°C (64°F). July tends to be warmer, showing a maximum temperature of 31°C (87°F), compared to September's high of 26°C (80°F). Additionally, July experiences more rainfall, with a total of 42 mm (1.6 in) over 9 days, versus September's 19 mm (0.8 in) spread across just 4 days. The humidity in September is slightly higher at 59%, compared to July's 49%. For more details about the weather in July, you can check Altai weather in July.
In comparing the weather between September and August, it is evident that September experiences a drop in average temperature, with minimums at -7°C (19°F) and an average of 9°C (49°F), compared to August’s minimum of 1°C (34°F) and an average of 15°C (59°F). While both months have similar maximum temperatures, September tends to be slightly cooler overall. September also sees a significant reduction in precipitation, with only 19 mm (0.8 in) over 4 days, compared to August's 66 mm (2.6 in) over 9 days, indicating a drier month. Additionally, September has higher humidity levels at 59%, compared to August's 54%, adding a unique characteristic to the early fall climate. For a more detailed perspective on August weather, you can visit Altai weather in August.
September and October show a notable transition in weather patterns. In September, temperatures range from a minimum of -7°C (19°F) to a maximum of 26°C (80°F), with an average of 9°C (49°F) and moderate precipitation of 19 mm (0.8 in) over four days. The humidity stands at 59%, contributing to a relatively comfortable feel.
In contrast, October brings a significant drop in temperatures, with minimums plummeting to -15°C (5°F) and maximums only reaching 19°C (66°F). The average temperature falls to 0°C (33°F), and while precipitation decreases to 10 mm (0.4 in) over the same number of days, the humidity rises to 67%, making the air feel colder. This shift marks the transition into the harsher conditions of winter. For more detailed information, check Altai weather in October.
In September, the weather tends to be milder, with temperatures ranging from a minimum of -7°C (19°F) to a maximum of 26°C (80°F) and an average of 9°C (49°F). This month experiences a bit more rainfall, totaling 19 mm (0.8 in) over approximately 4 days, alongside a moderate humidity level of 59%. In contrast, November ushers in much colder conditions, with temperatures plummeting to a minimum of -25°C (-13°F) and an average temperature of -7°C (19°F). The maximum temperature reaches only 11°C (53°F). November sees significantly less precipitation, at just 7 mm (0.3 in) over 1 day, coupled with higher humidity at 86%. For more detailed insights about the weather specifics in November, you can visit Altai weather in November.
In September, the weather is relatively mild, with temperatures ranging from a minimum of -7°C (19°F) to a maximum of 26°C (80°F) and an average of 9°C (49°F). This month typically experiences some precipitation, averaging 19 mm (0.8 in) over about 4 days, alongside a moderate humidity level of 59%. In stark contrast, December brings biting cold, with temperatures plummeting to a minimum of -31°C (-24°F) and an average of -15°C (5°F), reaching a maximum of just 0°C (33°F). Precipitation is minimal, at only 4 mm (0.2 in) over about 1 day, but the humidity spikes to a high of 96%. For more details on the chilly December conditions, visit Altai weather in December.
As September unfolds in Altai, the weather transitions into a refreshing yet variable phase, setting it apart from the preceding summer months. With temperatures fluctuating significantly—from the pleasant warmth of daytime highs to the crisp chill of nights—this month offers a unique blend of warmth and coolness that can surprise even the most seasoned travelers. The relatively low precipitation, falling on just a few days, coupled with a moderate humidity level, creates an inviting atmosphere for outdoor adventures. As the region begins to embrace the onset of autumn, visitors can experience the stunning transformation of the landscape, making it an ideal time for exploration. For a deeper understanding of seasonal shifts, check out Altai Climate.