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September Weather in Saint-Omer, France

Last updated: August 23, 2025

In September, the average temperature in Saint-Omer, France is a comfortable 15°C (60°F). However, temperatures can range from a chilly 4°C (39°F) at night to a warm 30°C (86°F) during the day. Expect about 55 mm (2.1 in) of precipitation over 9 days, accompanied by an average humidity of 80%.

September Temperature in Saint-Omer

In September in Saint-Omer, the average temperature is 15°C (60°F). Maximums can reach 30°C (86°F), and minimums can be as low as 4°C (39°F). This climate makes it a great time to explore Saint-Omer, so pack accordingly and enjoy the range of conditions.

September Weather in Saint-Omer: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Saint-Omer, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint-Omer, September typically has an average temperature of 15°C (60°F), with highs reaching up to 30°C (86°F) and lows dropping to around 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec414346505562656560554643
Data source: Temperature data for Saint-Omer 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 Saint-Omer

In Saint-Omer in September, the total precipitation amount is 55 mm (2.1 in) over the course of 9 days.

September Precipitation Trends in Saint-Omer

The chart displays monthly precipitation patterns in Saint-Omer, 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 Saint-Omer, September typically receives around 55 mm (2.1 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec6360643769715278558360100
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Saint-Omer

In Saint-Omer in September humidity is 80%. With an average temperature of 15°C (60°F), this humidity feels like a warm, sticky embrace that can make even the simplest stroll feel like a workout, leaving travelers yearning for a refreshing breeze or shade to escape the weight of the air.

September Average Humidity in Saint-Omer

This chart illustrates the average monthly humidity levels in Saint-Omer, 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 Saint-Omer is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%86%85%82%81%76%73%80%89%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Saint-Omer

In Saint-Omer in September, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Saint-Omer.

Maximum UV Index Levels in Saint-Omer for September

The chart shows the monthly maximum UV Index (UVI) for Saint-Omer 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 Saint-Omer typically reaches 5, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Saint-Omer 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 Saint-Omer Compares to Other Months

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

This table compares monthly weather conditions in Saint-Omer, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)63 mm (2.5 inches)91%low
February Weather6°C (43°F)60 mm (2.3 inches)89%low
March Weather8°C (46°F)64 mm (2.5 inches)86%moderate
April Weather10°C (50°F)37 mm (1.4 inches)85%moderate
May Weather13°C (56°F)69 mm (2.7 inches)82%high
June Weather17°C (63°F)70 mm (2.8 inches)81%very high
July Weather18°C (65°F)52 mm (2.0 inches)76%very high
August Weather18°C (65°F)77 mm (3.1 inches)73%high
September Weather15°C (60°F)55 mm (2.1 inches)80%moderate
October Weather13°C (55°F)83 mm (3.3 inches)89%moderate
November Weather8°C (47°F)60 mm (2.4 inches)92%low
December Weather6°C (43°F)100 mm (3.9 inches)92%low

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