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September Weather in Plymouth, United States

Last updated: June 24, 2025

In September, the average temperature in Plymouth, United States hovers around 24°C (75°F). Expect a minimum of 11°C (52°F) and stunning highs reaching up to 35°C (96°F). With an average humidity of 80%, it's a month of warmth and moisture, complemented by an anticipated 125 mm (4.9 in) of precipitation spread over about 11 days.

September Temperature in Plymouth

In September in Plymouth, the average temperature is 24°C (75°F), with maximums reaching up to 35°C (96°F) and minimums dropping as low as 11°C (52°F). It's advisable to pack light clothing for warm days and a sweater for cooler evenings during your travels.

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

The chart illustrates September temperature patterns in Plymouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Plymouth, September typically has an average temperature of 24°C (75°F), with highs reaching up to 35°C (96°F) and lows dropping to around 11°C (52°F).
JanFebMarAprMayJunJulAugSepOctNovDec445053627076807975665448
Data source: Temperature data for Plymouth 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 Plymouth

In Plymouth in September, the precipitation amount is 125 mm (4.9 in) over the course of 11 days.

September Precipitation Trends in Plymouth

The chart displays monthly precipitation patterns in Plymouth, 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 Plymouth, September typically receives around 125 mm (4.9 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec9095651001141491411701257596108
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Plymouth

In Plymouth in September humidity is 80%. With an average temperature of 24°C (75°F), this humidity feels like a warm, sticky blanket enveloping you, making travel slightly uncomfortable as sweat clings to your skin and the air feels thick, urging you to seek shade and hydration frequently.

September Average Humidity in Plymouth

This chart illustrates the average monthly humidity levels in Plymouth, 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 Plymouth is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%81%80%80%81%82%83%83%80%80%83%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Plymouth

In Plymouth in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Plymouth.

Maximum UV Index Levels in Plymouth for September

The chart shows the monthly maximum UV Index (UVI) for Plymouth 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 Plymouth typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec46810111011109853
Data source: Plymouth 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 Plymouth Compares to Other Months

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

This table compares monthly weather conditions in Plymouth, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather7°C (45°F)90 mm (3.5 inches)84%moderate
February Weather10°C (50°F)95 mm (3.7 inches)81%high
March Weather12°C (53°F)64 mm (2.5 inches)80%very high
April Weather17°C (62°F)100 mm (3.9 inches)80%very high
May Weather21°C (70°F)114 mm (4.5 inches)81%extreme
June Weather25°C (76°F)149 mm (5.9 inches)82%very high
July Weather27°C (80°F)141 mm (5.5 inches)83%extreme
August Weather26°C (79°F)170 mm (6.7 inches)82%very high
September Weather24°C (75°F)125 mm (4.9 inches)80%very high
October Weather19°C (67°F)75 mm (2.9 inches)79%very high
November Weather12°C (54°F)96 mm (3.8 inches)83%moderate
December Weather9°C (49°F)108 mm (4.2 inches)84%moderate

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