September Weather in Allendale, United States

Last updated: June 24, 2025

In September, the average temperature in Allendale, United States is a warm 26°C (78°F), with a minimum of 11°C (51°F) and a maximum reaching up to 38°C (101°F). Expect about 85 mm (3.3 in) of precipitation spread over 8 days, contributing to an average humidity level of 83%. Prepare for a mix of warmth and occasional showers!

September Temperature in Allendale

In September in Allendale, the average temperature is 26°C (78°F). Maximums can reach 38°C (101°F), while minimums can drop to as low as 11°C (51°F). Travelers should be prepared for warm days and cooler evenings, making it essential to pack accordingly for their visit.

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

The chart illustrates September temperature patterns in Allendale, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Allendale, September typically has an average temperature of 26°C (78°F), with highs reaching up to 38°C (101°F) and lows dropping to around 11°C (51°F).

Data source: Temperature data for Allendale generated using information from the Copernicus Climate Change Service.

September Precipitation in Allendale

In Allendale in September, the precipitation amount is 85 mm (3.3 in) over the course of 8 days.

September Precipitation Trends in Allendale

The chart displays monthly precipitation patterns in Allendale, 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 Allendale, September typically receives around 85 mm (3.3 inches) of precipitation spread over approximately 8 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Allendale

In Allendale in September, humidity is 83%. With an average temperature of 26°C (78°F), this humidity feels like a heavy blanket wrapping around you, making travel a sticky affair as sweat lingers on your skin and every step requires extra effort.

September Average Humidity in Allendale

This chart illustrates the average monthly humidity levels in Allendale, 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 Allendale is approximately 83%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Allendale

In Allendale in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Allendale.

Maximum UV Index Levels in Allendale for September

The chart shows the monthly maximum UV Index (UVI) for Allendale 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 Allendale typically reaches 9, which falls under the very high exposure category.

Data source: Allendale 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 Allendale Compares to Other Months

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

This table compares monthly weather conditions in Allendale, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	10°C (50°F)	81 mm (3.2 inches)	86%	moderate
February Weather	13°C (56°F)	104 mm (4.1 inches)	81%	high
March Weather	16°C (60°F)	73 mm (2.9 inches)	81%	very high
April Weather	19°C (66°F)	119 mm (4.7 inches)	79%	very high
May Weather	24°C (75°F)	94 mm (3.7 inches)	75%	extreme
June Weather	26°C (79°F)	121 mm (4.8 inches)	75%	extreme
July Weather	28°C (82°F)	143 mm (5.6 inches)	80%	extreme
August Weather	27°C (81°F)	142 mm (5.6 inches)	81%	extreme
September Weather	26°C (78°F)	85 mm (3.3 inches)	83%	very high
October Weather	21°C (71°F)	72 mm (2.8 inches)	78%	very high
November Weather	14°C (57°F)	63 mm (2.5 inches)	85%	high
December Weather	11°C (53°F)	126 mm (5.0 inches)	87%	moderate