September Weather in Spring, United States

Last updated: June 24, 2025

In Spring, United States, the average temperature in September hovers around 26°C (80°F). Prepare for a range that dips to a cool 12°C (54°F) and can soar up to a sweltering 37°C (100°F). Expect about 166 mm (6.5 in) of precipitation spread over 14 days, contributing to an average humidity of 73%.

September Temperature in Spring

In September in Spring, the average temperature is 26°C (80°F). Maximum temperatures can reach 37°C (100°F), while the minimum can dip as low as 12°C (54°F). This pleasant climate makes Spring an ideal destination for travelers looking to enjoy a variety of outdoor activities.

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

The chart illustrates September temperature patterns in Spring, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Spring, September typically has an average temperature of 26°C (80°F), with highs reaching up to 37°C (100°F) and lows dropping to around 12°C (54°F).

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

September Precipitation in Spring

In Spring in September, the precipitation amount is 166 mm (6.5 in) over a period of 14 days.

September Precipitation Trends in Spring

The chart displays monthly precipitation patterns in Spring, 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 Spring, September typically receives around 166 mm (6.5 inches) of precipitation spread over approximately 14 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 Spring

In Spring in September, humidity is 73%. With an average temperature of 26°C (80°F), this humidity feels like a warm embrace that clings to your skin, making outdoor exploration a bit sticky but still inviting, perfect for leisurely strolls in the shade or refreshing breaks by the water.

September Average Humidity in Spring

This chart illustrates the average monthly humidity levels in Spring, 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 Spring is approximately 73%, 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 Spring

In Spring in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Spring.

Maximum UV Index Levels in Spring for September

The chart shows the monthly maximum UV Index (UVI) for Spring 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 Spring typically reaches 10, which falls under the very high exposure category.

Data source: Spring 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 Spring Compares to Other Months

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

This table compares monthly weather conditions in Spring, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (54°F)	91 mm (3.6 inches)	78%	moderate
February Weather	14°C (57°F)	103 mm (4.1 inches)	81%	very high
March Weather	18°C (65°F)	86 mm (3.4 inches)	76%	very high
April Weather	21°C (70°F)	90 mm (3.6 inches)	79%	extreme
May Weather	25°C (77°F)	192 mm (7.6 inches)	79%	extreme
June Weather	28°C (82°F)	160 mm (6.3 inches)	74%	extreme
July Weather	29°C (84°F)	123 mm (4.9 inches)	71%	extreme
August Weather	29°C (84°F)	168 mm (6.6 inches)	68%	extreme
September Weather	26°C (80°F)	166 mm (6.5 inches)	73%	very high
October Weather	22°C (72°F)	104 mm (4.1 inches)	75%	very high
November Weather	16°C (62°F)	73 mm (2.9 inches)	78%	high
December Weather	14°C (57°F)	111 mm (4.4 inches)	84%	moderate