September Weather in Forestbrook, United States

Last updated: June 24, 2025

In September, the average temperature in Forestbrook, United States is a pleasant 25°C (77°F). You'll experience a comfortable range, with minimums dipping to 12°C (54°F) and maximums soaring to 34°C (93°F). Be prepared for some rain, as the region sees about 178 mm (7.0 in) of precipitation over 12 days. With an average humidity of 81%, it's a month to embrace the warm, tropical vibes!

September Temperature in Forestbrook

In September in Forestbrook, the average temperature is 25°C (77°F). The maximum can reach 34°C (93°F), and the minimum can be as low as 12°C (54°F). This pleasant temperature range makes Forestbrook an ideal destination for travelers looking to enjoy a mix of warmth and cooler evenings.

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

The chart illustrates September temperature patterns in Forestbrook, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Forestbrook, September typically has an average temperature of 25°C (77°F), with highs reaching up to 34°C (93°F) and lows dropping to around 12°C (54°F).

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

September Precipitation in Forestbrook

In Forestbrook in September, the precipitation amount is 178 mm (7.0 in) over the course of 12 days.

September Precipitation Trends in Forestbrook

The chart displays monthly precipitation patterns in Forestbrook, 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 Forestbrook, September typically receives around 178 mm (7.0 inches) of precipitation spread over approximately 12 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 Forestbrook

In Forestbrook in September, humidity is 81%. With an average temperature of 25°C (77°F), this humidity feels like walking through a warm, thick blanket, making traveling quite challenging as you may feel sticky and sluggish, requiring frequent breaks to stay refreshed and hydrated.

September Average Humidity in Forestbrook

This chart illustrates the average monthly humidity levels in Forestbrook, 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 Forestbrook is approximately 81%, 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 Forestbrook

In Forestbrook 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 Forestbrook.

Maximum UV Index Levels in Forestbrook for September

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

Data source: Forestbrook 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 Forestbrook Compares to Other Months

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

This table compares monthly weather conditions in Forestbrook, 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)	66 mm (2.6 inches)	83%	moderate
February Weather	12°C (54°F)	87 mm (3.4 inches)	79%	high
March Weather	14°C (58°F)	71 mm (2.8 inches)	79%	very high
April Weather	18°C (65°F)	94 mm (3.7 inches)	78%	very high
May Weather	23°C (73°F)	122 mm (4.8 inches)	78%	extreme
June Weather	25°C (78°F)	156 mm (6.2 inches)	78%	extreme
July Weather	27°C (81°F)	179 mm (7.0 inches)	82%	extreme
August Weather	27°C (80°F)	212 mm (8.4 inches)	81%	extreme
September Weather	25°C (77°F)	178 mm (7.0 inches)	81%	very high
October Weather	21°C (70°F)	61 mm (2.4 inches)	78%	very high
November Weather	14°C (57°F)	86 mm (3.4 inches)	82%	high
December Weather	11°C (52°F)	130 mm (5.1 inches)	84%	moderate