nomadseason

September Weather in Bristol, United States

Last updated: June 24, 2025

In Bristol, United States, the average temperature in September hovers around 17°C (63°F), with a minimum of 3°C (38°F) and a maximum reaching up to 32°C (89°F). Be prepared for 76 mm (3.0 in) of precipitation over approximately 7 days, and expect average humidity levels of around 80%.

September Temperature in Bristol

In September in Bristol, the average temperature is 17°C (63°F). Maximums can reach 32°C (89°F) and minimums can be as low as 3°C (38°F). This makes it an ideal time for travelers to enjoy a mix of warm days and cooler evenings while exploring the region.

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

The chart illustrates September temperature patterns in Bristol, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bristol, September typically has an average temperature of 17°C (63°F), with highs reaching up to 32°C (89°F) and lows dropping to around 3°C (38°F).
JanFebMarAprMayJunJulAugSepOctNovDec272834445465707063534030
Data source: Temperature data for Bristol 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 Bristol

In Bristol in September, the precipitation amount is 76 mm (3.0 in) over a period of 7 days.

September Precipitation Trends in Bristol

The chart displays monthly precipitation patterns in Bristol, 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 Bristol, September typically receives around 76 mm (3.0 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec87897412275651057776128111120
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Bristol

In Bristol in September humidity is 80%. With an average temperature of 17°C (63°F), this humidity feels like you're walking through a thick, warm blanket, making travel feel slightly stifling and requiring frequent breaks to stay comfortable.

September Average Humidity in Bristol

This chart illustrates the average monthly humidity levels in Bristol, 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 Bristol is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%86%84%79%79%86%85%83%80%77%80%81%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bristol

In Bristol in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Bristol.

Maximum UV Index Levels in Bristol for September

The chart shows the monthly maximum UV Index (UVI) for Bristol 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 Bristol typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2457910987532
Data source: Bristol 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 Bristol Compares to Other Months

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

This table compares monthly weather conditions in Bristol, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (27°F)87 mm (3.4 inches)85%low
February Weather-2°C (28°F)88 mm (3.5 inches)86%moderate
March Weather1°C (34°F)73 mm (2.9 inches)84%moderate
April Weather7°C (44°F)122 mm (4.8 inches)79%high
May Weather12°C (54°F)75 mm (2.9 inches)79%very high
June Weather18°C (65°F)65 mm (2.6 inches)86%very high
July Weather21°C (71°F)105 mm (4.1 inches)85%very high
August Weather21°C (71°F)76 mm (3.0 inches)83%very high
September Weather17°C (63°F)76 mm (3.0 inches)80%high
October Weather11°C (53°F)128 mm (5.0 inches)77%moderate
November Weather4°C (40°F)111 mm (4.4 inches)80%moderate
December Weather-1°C (31°F)120 mm (4.7 inches)81%low

Compare Bristol's Climate with Cities Worldwide