nomadseason

September Weather in Chelmsford, United Kingdom

Last updated: August 27, 2025

In September, the average temperature in Chelmsford, United Kingdom is a mild 15°C (60°F). Expect a range with a minimum of 3°C (38°F) and a delightful maximum of 27°C (81°F). This month also brings about 49 mm (1.9 in) of precipitation over 11 days, resulting in an average humidity of 80%. Perfect for enjoying the beauty of the season!

September Temperature in Chelmsford

In September in Chelmsford, the average temperature is 15°C (60°F), with maximums reaching 27°C (81°F) and minimums dipping as low as 3°C (38°F). This makes it a great time for travelers to enjoy mild weather while exploring the outdoors.

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

The chart illustrates September temperature patterns in Chelmsford, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Chelmsford, September typically has an average temperature of 15°C (60°F), with highs reaching up to 27°C (81°F) and lows dropping to around 3°C (38°F).
JanFebMarAprMayJunJulAugSepOctNovDec414345495562656459544643
Data source: Temperature data for Chelmsford 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 Chelmsford

In Chelmsford in September, the total precipitation amount is 49 mm (1.9 in) spread over 11 days.

September Precipitation Trends in Chelmsford

The chart displays monthly precipitation patterns in Chelmsford, 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 Chelmsford, September typically receives around 49 mm (1.9 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec515152296469617149804583
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Chelmsford

In Chelmsford 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 Chelmsford

This chart illustrates the average monthly humidity levels in Chelmsford, 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 Chelmsford 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 Chelmsford

In Chelmsford 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 Chelmsford.

Maximum UV Index Levels in Chelmsford for September

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

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

This table compares monthly weather conditions in Chelmsford, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)51 mm (2.0 inches)91%low
February Weather6°C (43°F)51 mm (2.0 inches)89%low
March Weather7°C (46°F)52 mm (2.0 inches)86%moderate
April Weather9°C (49°F)29 mm (1.1 inches)85%moderate
May Weather13°C (55°F)64 mm (2.5 inches)82%high
June Weather16°C (62°F)68 mm (2.7 inches)81%very high
July Weather18°C (65°F)61 mm (2.4 inches)76%very high
August Weather18°C (65°F)70 mm (2.8 inches)73%high
September Weather15°C (60°F)49 mm (1.9 inches)80%moderate
October Weather12°C (54°F)80 mm (3.1 inches)89%moderate
November Weather8°C (47°F)45 mm (1.8 inches)92%low
December Weather6°C (44°F)83 mm (3.3 inches)92%low

Compare Chelmsford's Climate with Cities Worldwide