nomadseason

September Weather in Waterville, United States

Last updated: June 24, 2025

In Waterville, United States, the average temperature in September hovers around 18°C (65°F). Expect a minimum of 2°C (36°F) and a peak of 33°C (91°F) during this time. Precipitation is notable, with 139 mm (5.5 in) of rain spread over 10 days, contributing to an average humidity level of 81%. Enjoy the dynamic weather as it transforms the landscape!

September Temperature in Waterville

In September in Waterville, the average temperature is 18°C (65°F), with maximums reaching 33°C (91°F) and minimums dropping as low as 2°C (36°F). This makes Waterville an ideal destination for travelers seeking a mix of comfortable days and cooler evenings.

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

The chart illustrates September temperature patterns in Waterville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Waterville, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (91°F) and lows dropping to around 2°C (36°F).
JanFebMarAprMayJunJulAugSepOctNovDec171633435971747064483424
Data source: Temperature data for Waterville 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 Waterville

In Waterville, in September, the total precipitation amount is 139 mm (5.5 in) accumulated over 10 days.

September Precipitation Trends in Waterville

The chart displays monthly precipitation patterns in Waterville, 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 Waterville, September typically receives around 139 mm (5.5 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec35396589136114112136139923746
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Waterville

In Waterville in September, humidity is 81%. With an average temperature of 18°C (65°F), this humidity feels like a thick blanket wrapping around you, making every step feel heavier and the air thick and sultry—a challenging environment for traveling.

September Average Humidity in Waterville

This chart illustrates the average monthly humidity levels in Waterville, 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 Waterville is approximately 81%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%90%85%84%78%80%81%81%81%84%88%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Waterville

In Waterville in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Waterville.

Maximum UV Index Levels in Waterville for September

The chart shows the monthly maximum UV Index (UVI) for Waterville 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 Waterville typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35589101098532
Data source: Waterville 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 Waterville Compares to Other Months

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

This table compares monthly weather conditions in Waterville, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-9°C (17°F)35 mm (1.4 inches)87%moderate
February Weather-9°C (17°F)39 mm (1.5 inches)90%moderate
March Weather1°C (33°F)65 mm (2.6 inches)85%moderate
April Weather6°C (44°F)89 mm (3.5 inches)84%very high
May Weather15°C (59°F)136 mm (5.3 inches)78%very high
June Weather22°C (72°F)114 mm (4.5 inches)80%very high
July Weather23°C (74°F)112 mm (4.4 inches)81%very high
August Weather21°C (71°F)136 mm (5.3 inches)81%very high
September Weather18°C (65°F)139 mm (5.5 inches)81%very high
October Weather9°C (49°F)91 mm (3.6 inches)84%moderate
November Weather1°C (34°F)37 mm (1.5 inches)88%moderate
December Weather-4°C (25°F)46 mm (1.8 inches)84%low

Compare Waterville's Climate with Cities Worldwide