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September Weather in Hamilton, United States

Last updated: June 24, 2025

The average temperature in Hamilton, United States during September is a warm 26°C (79°F), with minimums dropping to 9°C (48°F) and maximums soaring to 38°C (101°F). Expect precipitation of about 70 mm (2.8 in) over the course of 7 days and an average humidity of 66%, making it a month of delightful warmth mixed with the occasional refreshing shower.

September Temperature in Hamilton

In September in Hamilton, the average temperature is 26°C (79°F), with maximums reaching 38°C (101°F) and minimums dropping as low as 9°C (48°F). This variation in temperature makes it essential to pack both light clothing for the heat and warmer layers for the cooler evenings when traveling.

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

The chart illustrates September temperature patterns in Hamilton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hamilton, September typically has an average temperature of 26°C (79°F), with highs reaching up to 38°C (101°F) and lows dropping to around 9°C (48°F).
JanFebMarAprMayJunJulAugSepOctNovDec485061667481858579685752
Data source: Temperature data for Hamilton 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 Hamilton

In Hamilton in September, the precipitation amount is 70 mm (2.8 in) over a span of 7 days.

September Precipitation Trends in Hamilton

The chart displays monthly precipitation patterns in Hamilton, 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 Hamilton, September typically receives around 70 mm (2.8 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec46758079144764480701194242
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hamilton

In Hamilton in September, humidity is 66%. With an average temperature of 26°C (79°F), this humidity feels like a warm, enveloping blanket, making outdoor activities invigorating yet requiring occasional breaks in the shade to stay comfortable while traveling.

September Average Humidity in Hamilton

This chart illustrates the average monthly humidity levels in Hamilton, 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 Hamilton is approximately 66%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec78%78%77%78%82%78%69%63%66%73%84%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hamilton

In Hamilton in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Hamilton.

Maximum UV Index Levels in Hamilton for September

The chart shows the monthly maximum UV Index (UVI) for Hamilton 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 Hamilton typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec478101112121110864
Data source: Hamilton 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 Hamilton Compares to Other Months

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

This table compares monthly weather conditions in Hamilton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather9°C (48°F)46 mm (1.8 inches)78%moderate
February Weather10°C (50°F)75 mm (2.9 inches)78%high
March Weather16°C (61°F)80 mm (3.1 inches)77%very high
April Weather19°C (66°F)79 mm (3.1 inches)78%very high
May Weather24°C (75°F)144 mm (5.7 inches)82%extreme
June Weather27°C (82°F)76 mm (3.0 inches)78%extreme
July Weather30°C (86°F)44 mm (1.7 inches)69%extreme
August Weather29°C (85°F)80 mm (3.2 inches)63%extreme
September Weather26°C (79°F)70 mm (2.8 inches)66%very high
October Weather20°C (68°F)119 mm (4.7 inches)73%very high
November Weather14°C (58°F)42 mm (1.7 inches)84%high
December Weather11°C (53°F)42 mm (1.6 inches)87%moderate

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