nomadseason

September Weather in Hemel Hempstead, United Kingdom

Last updated: August 27, 2025

In September the average temperature in Hemel Hempstead, United Kingdom is a comfortable 15°C (59°F). Expect a range that can dip to a minimum of 3°C (38°F) and rise to a maximum of 28°C (83°F). During this month, you might encounter 51 mm (2.0 in) of precipitation spread over 10 days, contributing to an average humidity level of 82%. Prepare for a mix of weather as you explore!

September Temperature in Hemel Hempstead

In September in Hemel Hempstead, the average temperature is 15°C (59°F). The maximum can reach 28°C (83°F), while the minimum can drop as low as 3°C (38°F). Overall, this means travelers can expect mild weather perfect for exploring the outdoors.

September Weather in Hemel Hempstead: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Hemel Hempstead, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hemel Hempstead, September typically has an average temperature of 15°C (59°F), with highs reaching up to 28°C (83°F) and lows dropping to around 3°C (38°F).
JanFebMarAprMayJunJulAugSepOctNovDec404245495561656359534643
Data source: Temperature data for Hemel Hempstead 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 Hemel Hempstead

In Hemel Hempstead in September, the total precipitation amount is 51 mm (2.0 in) spread over a period of 10 days.

September Precipitation Trends in Hemel Hempstead

The chart displays monthly precipitation patterns in Hemel Hempstead, 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 Hemel Hempstead, September typically receives around 51 mm (2.0 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec565257346674677151915483
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Hemel Hempstead

In Hemel Hempstead in September, humidity is 82%. With an average temperature of 15°C (59°F), this humidity feels like a heavy blanket wrapping around you, making outdoor activities feel sticky and uncomfortable for travelers.

September Average Humidity in Hemel Hempstead

This chart illustrates the average monthly humidity levels in Hemel Hempstead, 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 Hemel Hempstead is approximately 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%86%85%79%81%71%76%82%91%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hemel Hempstead

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

Maximum UV Index Levels in Hemel Hempstead for September

The chart shows the monthly maximum UV Index (UVI) for Hemel Hempstead 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 Hemel Hempstead typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578876421
Data source: Hemel Hempstead 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 Hemel Hempstead Compares to Other Months

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

This table compares monthly weather conditions in Hemel Hempstead, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)56 mm (2.2 inches)91%low
February Weather6°C (43°F)52 mm (2.0 inches)89%low
March Weather7°C (45°F)57 mm (2.2 inches)86%moderate
April Weather9°C (49°F)34 mm (1.3 inches)85%moderate
May Weather13°C (55°F)66 mm (2.6 inches)79%high
June Weather16°C (61°F)74 mm (2.9 inches)80%very high
July Weather18°C (65°F)67 mm (2.6 inches)71%very high
August Weather17°C (64°F)71 mm (2.8 inches)76%high
September Weather15°C (59°F)51 mm (2.0 inches)82%high
October Weather11°C (53°F)91 mm (3.6 inches)90%moderate
November Weather8°C (46°F)54 mm (2.1 inches)92%low
December Weather6°C (43°F)83 mm (3.3 inches)92%low

Compare Hemel Hempstead's Climate with Cities Worldwide