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September Weather in Saint-Lo, France

Last updated: August 23, 2025

In Saint-Lo, France, the average temperature in September hovers around 15°C (60°F), making for a pleasant climate. However, temperatures can vary significantly, with a minimum dipping to 4°C (39°F) and a maximum soaring to 31°C (89°F). Expect about 58 mm (2.3 in) of precipitation spread across 11 days, contributing to an average humidity level of 79%. Ideal conditions for enjoying the unique charm of the season!

September Temperature in Saint-Lo

In September in Saint-Lo, the average temperature is 15°C (60°F), with maximums reaching up to 31°C (89°F) and minimums dropping as low as 4°C (39°F). It's a great time to visit for those who enjoy mild weather with the potential for warm days and cool nights.

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

The chart illustrates September temperature patterns in Saint-Lo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint-Lo, September typically has an average temperature of 15°C (60°F), with highs reaching up to 31°C (89°F) and lows dropping to around 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec424447515562656360544745
Data source: Temperature data for Saint-Lo 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-Lo

In Saint-Lo in September, the precipitation amount is 58 mm (2.3 in) over the course of 11 days.

September Precipitation Trends in Saint-Lo

The chart displays monthly precipitation patterns in Saint-Lo, 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-Lo, September typically receives around 58 mm (2.3 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec70778048859459665810384126
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Saint-Lo

In Saint-Lo in September, humidity is 79%. With an average temperature of 15°C (60°F), this humidity feels like a warm, enveloping blanket that can make traveling feel muggy and a bit stifling, requiring frequent breaks to stay refreshed and hydrated.

September Average Humidity in Saint-Lo

This chart illustrates the average monthly humidity levels in Saint-Lo, 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-Lo is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%89%86%85%80%80%69%73%79%89%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Saint-Lo

In Saint-Lo 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 Saint-Lo, you can refer to this Hourly UV Index in Saint-Lo.

Maximum UV Index Levels in Saint-Lo for September

The chart shows the monthly maximum UV Index (UVI) for Saint-Lo 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-Lo typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec234679886421
Data source: Saint-Lo 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-Lo Compares to Other Months

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

This table compares monthly weather conditions in Saint-Lo, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (42°F)70 mm (2.7 inches)90%low
February Weather7°C (44°F)77 mm (3.0 inches)89%moderate
March Weather8°C (47°F)79 mm (3.1 inches)86%moderate
April Weather10°C (51°F)48 mm (1.9 inches)84%high
May Weather13°C (56°F)85 mm (3.4 inches)80%high
June Weather16°C (62°F)94 mm (3.7 inches)80%very high
July Weather18°C (65°F)59 mm (2.3 inches)69%very high
August Weather17°C (64°F)66 mm (2.6 inches)73%very high
September Weather15°C (60°F)58 mm (2.3 inches)79%high
October Weather12°C (55°F)103 mm (4.0 inches)89%moderate
November Weather8°C (47°F)84 mm (3.3 inches)92%low
December Weather7°C (45°F)126 mm (5.0 inches)92%low

Compare Saint-Lo's Climate with Cities Worldwide