September Weather in Plainfield, United States

Last updated: June 24, 2025

In September, the average temperature in Plainfield, United States hovers around 19°C (66°F), creating a comfortable atmosphere for outdoor activities. Expect a minimum temperature of 4°C (39°F) and a maximum of 34°C (93°F), offering a wide range for weather enthusiasts. Be prepared for some rain, as precipitation totals 97 mm (3.8 in) over about 9 days. With an average humidity level of 75%, Plainfield exhibits a warm and inviting climate perfect for exploration.

September Temperature in Plainfield

In September in Plainfield, the average temperature is 19°C (66°F), with maximums reaching 34°C (93°F) and minimums dropping as low as 4°C (39°F). It's a wonderful time for travelers to experience comfortable weather while enjoying outdoor activities.

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

The chart illustrates September temperature patterns in Plainfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Plainfield, September typically has an average temperature of 19°C (66°F), with highs reaching up to 34°C (93°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Plainfield

In Plainfield in September, the total precipitation amount reaches 97 mm (3.8 in) over the course of 9 days.

September Precipitation Trends in Plainfield

The chart displays monthly precipitation patterns in Plainfield, 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 Plainfield, September typically receives around 97 mm (3.8 inches) of precipitation spread over approximately 9 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 Plainfield

In Plainfield in September humidity is 75%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it slightly uncomfortable for traveling as you navigate through the thick, muggy air.

September Average Humidity in Plainfield

This chart illustrates the average monthly humidity levels in Plainfield, 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 Plainfield 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 Plainfield

In Plainfield 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 Plainfield.

Maximum UV Index Levels in Plainfield for September

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

Data source: Plainfield 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 Plainfield Compares to Other Months

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

This table compares monthly weather conditions in Plainfield, 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 (31°F)	70 mm (2.7 inches)	84%	moderate
February Weather	1°C (33°F)	88 mm (3.5 inches)	84%	moderate
March Weather	3°C (38°F)	94 mm (3.7 inches)	82%	high
April Weather	9°C (48°F)	129 mm (5.1 inches)	79%	very high
May Weather	15°C (59°F)	111 mm (4.4 inches)	75%	very high
June Weather	20°C (68°F)	102 mm (4.0 inches)	78%	very high
July Weather	23°C (74°F)	166 mm (6.5 inches)	76%	very high
August Weather	23°C (73°F)	123 mm (4.8 inches)	76%	very high
September Weather	19°C (66°F)	97 mm (3.8 inches)	75%	very high
October Weather	13°C (56°F)	135 mm (5.3 inches)	75%	high
November Weather	6°C (43°F)	100 mm (3.9 inches)	80%	moderate
December Weather	1°C (34°F)	129 mm (5.1 inches)	80%	low