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September Weather in Gossau, Switzerland

Last updated: August 27, 2025

In Gossau, Switzerland, the average temperature in September hovers around 15°C (59°F), with the mercury dipping as low as 4°C (40°F) and climbing to a warm 27°C (80°F). Be prepared for some rain, as the region receives an average precipitation of 128 mm (5.0 in) over the course of 13 days. Additionally, the average humidity levels are quite high at 83%, making for a notably moist atmosphere.

September Temperature in Gossau

In September in Gossau, the average temperature is 15°C (59°F). Maximums can reach 27°C (80°F), and minimums can be as low as 4°C (40°F). Be sure to pack a variety of clothing to comfortably enjoy both warm and cooler moments during your travels.

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

The chart illustrates September temperature patterns in Gossau, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Gossau, September typically has an average temperature of 15°C (59°F), with highs reaching up to 27°C (80°F) and lows dropping to around 4°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec333642495565666659514136
Data source: Temperature data for Gossau 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 Gossau

In Gossau in September, the precipitation amount is 128 mm (5.0 in) spread over 13 days.

September Precipitation Trends in Gossau

The chart displays monthly precipitation patterns in Gossau, 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 Gossau, September typically receives around 128 mm (5.0 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec106851007914716915919512811972135
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Gossau

In Gossau in September humidity is 83%. With an average temperature of 15°C (59°F), this humidity feels like a cozy, damp embrace that can be quite stifling for traveling, making even short walks feel more exhausting than they should, and prompting a need for frequent breaks in shaded or air-conditioned areas.

September Average Humidity in Gossau

This chart illustrates the average monthly humidity levels in Gossau, 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 Gossau is approximately 83%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%89%87%84%80%82%83%80%83%90%89%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Gossau

In Gossau 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 Gossau, you can refer to this Hourly UV Index in Gossau.

Maximum UV Index Levels in Gossau for September

The chart shows the monthly maximum UV Index (UVI) for Gossau 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 Gossau typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689986421
Data source: Gossau 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 Gossau Compares to Other Months

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

This table compares monthly weather conditions in Gossau, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (33°F)106 mm (4.2 inches)92%low
February Weather2°C (37°F)85 mm (3.3 inches)89%moderate
March Weather5°C (42°F)100 mm (3.9 inches)87%moderate
April Weather9°C (49°F)79 mm (3.1 inches)84%high
May Weather13°C (56°F)147 mm (5.8 inches)80%very high
June Weather18°C (65°F)168 mm (6.6 inches)82%very high
July Weather19°C (67°F)159 mm (6.3 inches)83%very high
August Weather19°C (66°F)194 mm (7.7 inches)80%very high
September Weather15°C (59°F)128 mm (5.0 inches)83%high
October Weather10°C (51°F)119 mm (4.7 inches)90%moderate
November Weather5°C (42°F)72 mm (2.8 inches)88%low
December Weather2°C (36°F)135 mm (5.3 inches)90%low

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