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September Weather in Caldwell, United States

Last updated: June 24, 2025

In September, the average temperature in Caldwell, United States hovers around 20°C (68°F). Expect a pleasant range, with minimums dipping to 5°C (41°F) and maximums soaring to 39°C (103°F). Precipitation is relatively low, averaging just 9 mm (0.4 in) over 2 days, complemented by a comfortable average humidity of 48%.

September Temperature in Caldwell

In September in Caldwell, the average temperature is 20°C (68°F). Maximums can reach 39°C (103°F), and minimums can be as low as 5°C (41°F). This diverse range of temperatures makes Caldwell an exciting destination for travelers seeking both warmth and cooler escapes.

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 (68°F), with highs reaching up to 39°C (103°F) and lows dropping to around 5°C (41°F).
JanFebMarAprMayJunJulAugSepOctNovDec343747546372827968544335
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 precipitation amount is 9 mm (0.4 in) over the course of 2 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 9 mm (0.4 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec424331292816169182833
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 48%. With an average temperature of 20°C (68°F), this humidity feels like a pleasant and refreshing environment for traveling, creating an ideal atmosphere for exploring and enjoying outdoor activities.

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 48%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%89%85%79%71%71%66%50%48%65%84%87%
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.
JanFebMarAprMayJunJulAugSepOctNovDec346810111098542
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 Weather1°C (34°F)42 mm (1.7 inches)88%moderate
February Weather3°C (37°F)43 mm (1.7 inches)89%moderate
March Weather8°C (47°F)31 mm (1.2 inches)85%high
April Weather12°C (54°F)29 mm (1.2 inches)79%very high
May Weather17°C (63°F)28 mm (1.1 inches)71%very high
June Weather22°C (73°F)16 mm (0.6 inches)71%extreme
July Weather28°C (82°F)1 mm (0.0 inches)66%very high
August Weather26°C (80°F)5 mm (0.2 inches)50%very high
September Weather20°C (68°F)9 mm (0.4 inches)48%very high
October Weather12°C (54°F)18 mm (0.7 inches)65%moderate
November Weather6°C (43°F)28 mm (1.1 inches)84%moderate
December Weather2°C (35°F)33 mm (1.3 inches)87%low

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