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September Weather in Hamilton, United States

Last updated: June 24, 2025

In Hamilton, United States, the average temperature in September is a comfortable 21°C (70°F). Expect minimums dipping to 6°C (43°F) and maximums soaring up to 34°C (94°F). With an average precipitation of 81 mm (3.2 in) spread over 8 days, and humidity levels around 73%, it's a month that embraces both warmth and occasional refreshing showers.

September Temperature in Hamilton

In September in Hamilton, the average temperature is 21°C (70°F), with maximums reaching 34°C (94°F) and minimums dropping as low as 6°C (43°F). This varied climate makes it an ideal destination for travelers looking to experience a mix of warm days and cooler evenings.

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 21°C (70°F), with highs reaching up to 34°C (94°F) and lows dropping to around 6°C (43°F).
JanFebMarAprMayJunJulAugSepOctNovDec323544536573777470584337
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 81 mm (3.2 in) over the course of 8 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 81 mm (3.2 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec81108130109130137117948110098103
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 73%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace that can make outdoor activities feel sweltering, so it's essential to stay hydrated and take breaks in the shade while exploring.

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 73%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%87%85%81%82%81%73%73%78%89%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 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 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 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098643
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 Weather0°C (32°F)81 mm (3.2 inches)88%moderate
February Weather2°C (36°F)108 mm (4.2 inches)88%moderate
March Weather7°C (44°F)130 mm (5.1 inches)87%high
April Weather12°C (53°F)109 mm (4.3 inches)85%very high
May Weather18°C (65°F)130 mm (5.1 inches)81%very high
June Weather23°C (73°F)137 mm (5.4 inches)82%very high
July Weather25°C (77°F)117 mm (4.6 inches)81%very high
August Weather24°C (75°F)94 mm (3.7 inches)73%very high
September Weather21°C (70°F)81 mm (3.2 inches)73%very high
October Weather15°C (59°F)100 mm (3.9 inches)78%high
November Weather6°C (43°F)98 mm (3.9 inches)89%moderate
December Weather3°C (38°F)103 mm (4.0 inches)87%moderate

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