September Weather in Westfield, United States

Last updated: June 24, 2025

In September, the average temperature in Westfield, United States hovers around 18°C (64°F), with a minimum that can dip to 5°C (42°F) and a maximum reaching up to 30°C (87°F). Expect 87 mm (3.4 in) of precipitation spread across 11 days, contributing to an average humidity of 76%. Stay prepared for a mix of weather!

September Temperature in Westfield

In September in Westfield, the average temperature is 18°C (64°F). Maximums can reach 30°C (87°F), while minimums can drop as low as 5°C (42°F). This range makes it an ideal time for travelers to enjoy a variety of outdoor activities, from exploring the sights to relaxing in pleasant weather.

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

The chart illustrates September temperature patterns in Westfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Westfield, September typically has an average temperature of 18°C (64°F), with highs reaching up to 30°C (87°F) and lows dropping to around 5°C (42°F).

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

September Precipitation in Westfield

In Westfield in September, the precipitation amount is 87 mm (3.4 in) over the course of 11 days.

September Precipitation Trends in Westfield

The chart displays monthly precipitation patterns in Westfield, 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 Westfield, September typically receives around 87 mm (3.4 inches) of precipitation spread over approximately 11 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 Westfield

In Westfield in September, humidity is 76%. With an average temperature of 18°C (64°F), this humidity feels like a warm blanket wrapping around you, making outdoor activities feel steamy and invigorating—perfect for exploring charming streets, though you might want to take breaks in the shade.

September Average Humidity in Westfield

This chart illustrates the average monthly humidity levels in Westfield, 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 Westfield is approximately 76%, 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 Westfield

In Westfield 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 Westfield.

Maximum UV Index Levels in Westfield for September

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

Data source: Westfield 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 Westfield Compares to Other Months

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

This table compares monthly weather conditions in Westfield, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	103 mm (4.1 inches)	91%	low
February Weather	-2°C (29°F)	104 mm (4.1 inches)	91%	moderate
March Weather	1°C (35°F)	100 mm (3.9 inches)	88%	high
April Weather	7°C (45°F)	126 mm (4.9 inches)	88%	very high
May Weather	14°C (57°F)	122 mm (4.8 inches)	82%	very high
June Weather	19°C (67°F)	129 mm (5.1 inches)	79%	very high
July Weather	22°C (72°F)	155 mm (6.1 inches)	77%	very high
August Weather	21°C (70°F)	111 mm (4.4 inches)	72%	very high
September Weather	18°C (64°F)	87 mm (3.4 inches)	76%	very high
October Weather	12°C (54°F)	152 mm (6.0 inches)	83%	high
November Weather	4°C (40°F)	129 mm (5.1 inches)	88%	moderate
December Weather	1°C (33°F)	124 mm (4.9 inches)	87%	low