September Weather in Pleasanton, United States

Last updated: June 24, 2025

In September, the average temperature in Pleasanton, United States hovers around 23°C (73°F), offering a pleasant climate. However, be prepared for a temperature range that can dip to a minimum of 5°C (41°F) and soar to a maximum of 34°C (93°F). During this month, expect approximately 77 mm (3.0 in) of precipitation spread over 7 days, contributing to a comfortable average humidity of 72%.

September Temperature in Pleasanton

In September in Pleasanton, the average temperature is 23°C (73°F). The maximum can reach 34°C (93°F) while the minimum can dip as low as 5°C (41°F). This variation makes it essential for travelers to pack layers to enjoy the pleasant daytime warmth as well as to prepare for cooler evenings.

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

The chart illustrates September temperature patterns in Pleasanton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Pleasanton, September typically has an average temperature of 23°C (73°F), with highs reaching up to 34°C (93°F) and lows dropping to around 5°C (41°F).

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

September Precipitation in Pleasanton

In Pleasanton in September, the precipitation amount is 77 mm (3.0 in) over the course of 7 days.

September Precipitation Trends in Pleasanton

The chart displays monthly precipitation patterns in Pleasanton, 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 Pleasanton, September typically receives around 77 mm (3.0 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 Pleasanton

In Pleasanton in September, humidity is 72%. With an average temperature of 23°C (73°F), this humidity feels like a warm embrace, making travel exhilarating yet slightly sticky, as the air clings to your skin and invites you to seek out cool, refreshing places to explore.

September Average Humidity in Pleasanton

This chart illustrates the average monthly humidity levels in Pleasanton, 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 Pleasanton is approximately 72%, 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 Pleasanton

In Pleasanton 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 Pleasanton.

Maximum UV Index Levels in Pleasanton for September

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

Data source: Pleasanton 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 Pleasanton Compares to Other Months

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

This table compares monthly weather conditions in Pleasanton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (34°F)	63 mm (2.5 inches)	80%	moderate
February Weather	2°C (35°F)	49 mm (1.9 inches)	78%	moderate
March Weather	9°C (48°F)	107 mm (4.2 inches)	75%	high
April Weather	13°C (56°F)	111 mm (4.4 inches)	77%	very high
May Weather	19°C (67°F)	186 mm (7.3 inches)	82%	very high
June Weather	25°C (78°F)	93 mm (3.6 inches)	83%	extreme
July Weather	27°C (81°F)	129 mm (5.1 inches)	81%	extreme
August Weather	25°C (77°F)	120 mm (4.7 inches)	78%	very high
September Weather	23°C (73°F)	77 mm (3.0 inches)	72%	very high
October Weather	15°C (58°F)	106 mm (4.2 inches)	72%	high
November Weather	8°C (46°F)	47 mm (1.9 inches)	84%	moderate
December Weather	4°C (40°F)	33 mm (1.3 inches)	86%	moderate