nomadseason

September Weather in Bayan, Mongolia

Last updated: August 28, 2025

In September, the average temperature in Bayan, Mongolia hovers around 8°C (47°F). However, temperatures can fluctuate significantly, with minimums plunging to -8°C (18°F) and maximums soaring up to 27°C (81°F). This month also sees an average precipitation of 35 mm (1.4 in) spread over 8 days, combined with a comfortable average humidity of 78%.

September Temperature in Bayan

In September in Bayan, the average temperature is 8°C (47°F). Maximum temperatures can reach 27°C (81°F), while minimums can drop as low as -8°C (18°F). Be prepared for a wide range of temperatures when traveling during this month.

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

The chart illustrates September temperature patterns in Bayan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bayan, September typically has an average temperature of 8°C (47°F), with highs reaching up to 27°C (81°F) and lows dropping to around -8°C (18°F).
JanFebMarAprMayJunJulAugSepOctNovDec-622136485961574630140
Data source: Temperature data for Bayan generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Bayan

In Bayan in September, the precipitation amount is 35 mm (1.4 in) over the course of 8 days.

September Precipitation Trends in Bayan

The chart displays monthly precipitation patterns in Bayan, 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 Bayan, September typically receives around 35 mm (1.4 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec251029287799111352062
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Bayan

In Bayan in September, humidity is 78%. With an average temperature of 8°C (47°F), this humidity feels like a chilly embrace, making travel invigorating yet damp, as the cool air wraps around you, emphasizing the need for layers to stay comfortable while exploring.

September Average Humidity in Bayan

This chart illustrates the average monthly humidity levels in Bayan, 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 Bayan is approximately 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec94%89%84%80%71%71%75%74%78%86%94%96%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bayan

In Bayan in September, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Bayan, you can refer to this Hourly UV Index in Bayan.

Maximum UV Index Levels in Bayan for September

The chart shows the monthly maximum UV Index (UVI) for Bayan 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 Bayan typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235799986421
Data source: Bayan 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.

How September Weather in Bayan Compares to Other Months

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

This table compares monthly weather conditions in Bayan, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-21°C (-6°F)2 mm (0.1 inches)94%low
February Weather-17°C (2°F)5 mm (0.2 inches)89%moderate
March Weather-6°C (21°F)10 mm (0.4 inches)84%moderate
April Weather2°C (36°F)29 mm (1.1 inches)80%high
May Weather9°C (49°F)28 mm (1.1 inches)71%very high
June Weather15°C (59°F)77 mm (3.0 inches)71%very high
July Weather16°C (62°F)99 mm (3.9 inches)75%very high
August Weather14°C (57°F)110 mm (4.3 inches)74%very high
September Weather8°C (47°F)35 mm (1.4 inches)78%high
October Weather-1°C (30°F)20 mm (0.8 inches)86%moderate
November Weather-10°C (14°F)6 mm (0.2 inches)94%low
December Weather-18°C (1°F)2 mm (0.1 inches)96%low

Compare Bayan's Climate with Cities Worldwide