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September Weather in Harlow, United Kingdom

Last updated: August 27, 2025

In September, the average temperature in Harlow, United Kingdom hovers around 15°C (59°F), with minimums dipping to 4°C (39°F) and maximums reaching up to 28°C (83°F). Expect about 47 mm (1.9 in) of precipitation spread over 10 days, accompanied by an average humidity level of 80%.

September Temperature in Harlow

In September in Harlow, the average temperature is 15°C (59°F), with maximums reaching 28°C (83°F) and minimums dropping as low as 4°C (39°F). This mild climate makes it an ideal time for travelers to explore and enjoy outdoor activities.

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

The chart illustrates September temperature patterns in Harlow, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Harlow, 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 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec404345495561656459534643
Data source: Temperature data for Harlow 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 Harlow

In Harlow in September, the precipitation amount is 47 mm (1.9 in) over a span of 10 days.

September Precipitation Trends in Harlow

The chart displays monthly precipitation patterns in Harlow, 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 Harlow, September typically receives around 47 mm (1.9 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec534954316474677447834783
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Harlow

In Harlow in September, humidity is 80%. With an average temperature of 15°C (59°F), this humidity feels like a warm blanket enveloping you, making outdoor activities slightly uncomfortable and necessitating frequent breaks to stay hydrated.

September Average Humidity in Harlow

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

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

Maximum UV Index Levels in Harlow for September

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

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

This table compares monthly weather conditions in Harlow, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)53 mm (2.1 inches)91%low
February Weather6°C (43°F)49 mm (1.9 inches)89%low
March Weather7°C (45°F)54 mm (2.1 inches)86%moderate
April Weather9°C (49°F)31 mm (1.2 inches)85%moderate
May Weather13°C (55°F)64 mm (2.5 inches)82%high
June Weather16°C (62°F)74 mm (2.9 inches)81%very high
July Weather18°C (65°F)67 mm (2.6 inches)76%very high
August Weather18°C (64°F)74 mm (2.9 inches)73%high
September Weather15°C (59°F)47 mm (1.9 inches)80%high
October Weather12°C (53°F)83 mm (3.3 inches)89%moderate
November Weather8°C (46°F)47 mm (1.8 inches)92%low
December Weather6°C (43°F)83 mm (3.3 inches)92%low

Compare Harlow's Climate with Cities Worldwide