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September Weather in Caldwell, United States

Last updated: June 24, 2025

In Caldwell, United States, the average temperature in September is a pleasant 20°C (69°F). However, temperatures can vary significantly, dipping to a minimum of 5°C (42°F) and soaring to a maximum of 35°C (96°F). Expect some moisture in the air, with 109 mm (4.3 in) of precipitation over approximately 9 days. Overall, humidity sits at a comfortable 73%, making it a unique time to experience the climate!

September Temperature in Caldwell

In September in Caldwell, the average temperature is 20°C (69°F). Maximum can reach 35°C (96°F) and minimum can be as low as 5°C (42°F). This variation in temperatures makes Caldwell an ideal destination for travelers seeking both warm and cool experiences.

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

The chart illustrates September temperature patterns in Caldwell, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Caldwell, September typically has an average temperature of 20°C (69°F), with highs reaching up to 35°C (96°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec323643536471757369584337
Data source: Temperature data for Caldwell 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 Caldwell

In Caldwell in September, the total precipitation amount is 109 mm (4.3 in) spread over 9 days.

September Precipitation Trends in Caldwell

The chart displays monthly precipitation patterns in Caldwell, 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 Caldwell, September typically receives around 109 mm (4.3 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec9212312214314716912610610911390116
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Caldwell

In Caldwell in September humidity is 73%. With an average temperature of 20°C (69°F), this humidity feels like a warm embrace, making travel slightly sticky but ultimately comfortable as long as you stay hydrated and take breaks in the shade.

September Average Humidity in Caldwell

This chart illustrates the average monthly humidity levels in Caldwell, 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 Caldwell is approximately 73%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%88%87%82%84%82%73%74%81%89%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Caldwell

In Caldwell 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 Caldwell.

Maximum UV Index Levels in Caldwell for September

The chart shows the monthly maximum UV Index (UVI) for Caldwell 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 Caldwell typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098643
Data source: Caldwell 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 Caldwell Compares to Other Months

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

This table compares monthly weather conditions in Caldwell, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)91 mm (3.6 inches)88%moderate
February Weather2°C (37°F)123 mm (4.8 inches)88%moderate
March Weather6°C (44°F)122 mm (4.8 inches)88%high
April Weather12°C (53°F)143 mm (5.6 inches)86%very high
May Weather18°C (64°F)147 mm (5.8 inches)82%very high
June Weather22°C (71°F)169 mm (6.7 inches)84%very high
July Weather24°C (76°F)126 mm (4.9 inches)82%very high
August Weather23°C (74°F)106 mm (4.2 inches)73%very high
September Weather20°C (69°F)109 mm (4.3 inches)73%very high
October Weather15°C (58°F)113 mm (4.5 inches)81%high
November Weather6°C (43°F)90 mm (3.6 inches)89%moderate
December Weather3°C (38°F)116 mm (4.6 inches)86%moderate

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