September Weather in Pierce, United States

Last updated: June 24, 2025

In September, the average temperature in Pierce, United States is a pleasant 19°C (67°F). However, temperatures can vary significantly, with a minimum as low as 4°C (39°F) and a maximum reaching 34°C (93°F). Expect about 73 mm (2.9 in) of precipitation over approximately 7 days, contributing to an average humidity of 75%.

September Temperature in Pierce

In September in Pierce, the average temperature is 19°C (67°F) with maximums reaching up to 34°C (93°F) and minimums dropping as low as 4°C (39°F). Travelers should prepare for a wide range of temperatures and pack accordingly for both warm and cool experiences.

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

The chart illustrates September temperature patterns in Pierce, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Pierce, September typically has an average temperature of 19°C (67°F), with highs reaching up to 34°C (93°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Pierce

In Pierce in September, the precipitation amount is 73 mm (2.9 in) during a span of 7 days.

September Precipitation Trends in Pierce

The chart displays monthly precipitation patterns in Pierce, 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 Pierce, September typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 7 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 Pierce

In Pierce in September humidity is 75%. With an average temperature of 19°C (67°F), this humidity feels like a warm embrace, making travel invigorating yet slightly sticky, as you navigate through the vibrant streets or scenic landscapes.

September Average Humidity in Pierce

This chart illustrates the average monthly humidity levels in Pierce, 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 Pierce is approximately 75%, 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 Pierce

In Pierce 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 Pierce.

Maximum UV Index Levels in Pierce for September

The chart shows the monthly maximum UV Index (UVI) for Pierce 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 Pierce typically reaches 8, which falls under the very high exposure category.

Data source: Pierce 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 Pierce Compares to Other Months

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

This table compares monthly weather conditions in Pierce, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (23°F)	26 mm (1.0 inches)	77%	moderate
February Weather	-5°C (23°F)	25 mm (1.0 inches)	81%	moderate
March Weather	3°C (38°F)	83 mm (3.3 inches)	71%	high
April Weather	8°C (47°F)	71 mm (2.8 inches)	75%	very high
May Weather	15°C (60°F)	146 mm (5.7 inches)	74%	very high
June Weather	23°C (74°F)	86 mm (3.4 inches)	82%	extreme
July Weather	24°C (76°F)	82 mm (3.2 inches)	84%	very high
August Weather	23°C (73°F)	87 mm (3.4 inches)	82%	very high
September Weather	19°C (67°F)	73 mm (2.9 inches)	75%	very high
October Weather	10°C (50°F)	79 mm (3.1 inches)	72%	high
November Weather	3°C (38°F)	24 mm (0.9 inches)	81%	moderate
December Weather	-2°C (29°F)	44 mm (1.8 inches)	79%	low