September Weather in Fairfield, United States

Last updated: June 24, 2025

In September, the average temperature in Fairfield, United States hovers around 14°C (58°F). Expect a range where the minimum can dip to -3°C (27°F), while the maximum might soar to 35°C (94°F). There’s a moderate precipitation of 38 mm (1.5 in) spread over 6 days, accompanied by an average humidity of 68%. Prepare for variability in your weather experience!

September Temperature in Fairfield

In September in Fairfield, the average temperature is 14°C (58°F). Maximum temperatures can reach 35°C (94°F), while minimums can drop as low as -3°C (27°F). Make sure to pack for a wide range of weather conditions while traveling during this month.

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

The chart illustrates September temperature patterns in Fairfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fairfield, September typically has an average temperature of 14°C (58°F), with highs reaching up to 35°C (94°F) and lows dropping to around -3°C (27°F).

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

September Precipitation in Fairfield

In Fairfield in September, the total precipitation amount is 38 mm (1.5 in) spread over 6 days.

September Precipitation Trends in Fairfield

The chart displays monthly precipitation patterns in Fairfield, 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 Fairfield, September typically receives around 38 mm (1.5 inches) of precipitation spread over approximately 6 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 Fairfield

In Fairfield in September, humidity is 68%. With an average temperature of 14°C (58°F), this humidity feels like a damp embrace, making it a bit challenging for traveling. The air feels heavy, and you may find yourself needing to take breaks more often as you explore the sights.

September Average Humidity in Fairfield

This chart illustrates the average monthly humidity levels in Fairfield, 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 Fairfield is approximately 68%, 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 Fairfield

In Fairfield in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Fairfield.

Maximum UV Index Levels in Fairfield for September

The chart shows the monthly maximum UV Index (UVI) for Fairfield 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 Fairfield typically reaches 7, which falls under the high exposure category.

Data source: Fairfield 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 Fairfield Compares to Other Months

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

This table compares monthly weather conditions in Fairfield, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	13 mm (0.5 inches)	87%	low
February Weather	-7°C (19°F)	35 mm (1.4 inches)	88%	moderate
March Weather	0°C (33°F)	25 mm (1.0 inches)	83%	moderate
April Weather	5°C (41°F)	54 mm (2.1 inches)	78%	high
May Weather	12°C (53°F)	75 mm (2.9 inches)	76%	very high
June Weather	17°C (63°F)	80 mm (3.1 inches)	78%	very high
July Weather	21°C (71°F)	9 mm (0.4 inches)	77%	very high
August Weather	20°C (68°F)	20 mm (0.8 inches)	71%	very high
September Weather	14°C (58°F)	38 mm (1.5 inches)	68%	high
October Weather	6°C (44°F)	33 mm (1.3 inches)	72%	moderate
November Weather	2°C (36°F)	24 mm (0.9 inches)	84%	moderate
December Weather	-2°C (28°F)	23 mm (0.9 inches)	90%	low