September Weather in Milpitas, United States

Last updated: June 24, 2025

In Milpitas, United States, the average temperature in September hovers around 20°C (69°F). Visitors can expect a range, with temperatures dipping as low as 8°C (47°F) and peaking at a sizzling 43°C (110°F). Rainfall is minimal, averaging just 2 mm (0.1 in) across 0 days, while humidity remains reasonably comfortable at 55%. Enjoy the pleasant weather!

September Temperature in Milpitas

In September in Milpitas, the average temperature is 20°C (69°F). The maximum can reach 43°C (110°F) and the minimum can be as low as 8°C (47°F). It's important to pack for both warmth and heat when traveling during this month.

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

The chart illustrates September temperature patterns in Milpitas, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Milpitas, September typically has an average temperature of 20°C (69°F), with highs reaching up to 43°C (110°F) and lows dropping to around 8°C (47°F).

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

September Precipitation in Milpitas

In Milpitas in September, the precipitation amount is 2 mm (0.1 in) during a span of 0 days.

September Precipitation Trends in Milpitas

The chart displays monthly precipitation patterns in Milpitas, 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 Milpitas, September typically receives around 2 mm (0.1 inches) of precipitation spread over approximately 0 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Milpitas

In Milpitas in September humidity is 55%. With an average temperature of 20°C (69°F), this humidity feels like a refreshing embrace, making it ideal for exploring the local sights while still requiring a light layer to stay comfortable.

September Average Humidity in Milpitas

This chart illustrates the average monthly humidity levels in Milpitas, 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 Milpitas is approximately 55%, 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 Milpitas

In Milpitas 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 Milpitas.

Maximum UV Index Levels in Milpitas for September

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

Data source: Milpitas 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 Milpitas Compares to Other Months

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

This table compares monthly weather conditions in Milpitas, 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 (51°F)	98 mm (3.9 inches)	82%	moderate
February Weather	11°C (52°F)	95 mm (3.8 inches)	84%	moderate
March Weather	12°C (54°F)	87 mm (3.4 inches)	82%	very high
April Weather	14°C (57°F)	30 mm (1.2 inches)	78%	very high
May Weather	16°C (61°F)	23 mm (0.9 inches)	71%	very high
June Weather	19°C (66°F)	1 mm (0.0 inches)	64%	extreme
July Weather	20°C (69°F)	0 mm (0.0 inches)	58%	extreme
August Weather	21°C (70°F)	0 mm (0.0 inches)	54%	very high
September Weather	20°C (69°F)	2 mm (0.1 inches)	55%	very high
October Weather	18°C (64°F)	22 mm (0.9 inches)	62%	high
November Weather	13°C (56°F)	40 mm (1.6 inches)	78%	moderate
December Weather	10°C (51°F)	81 mm (3.2 inches)	80%	moderate