September Weather in Derby, United States

Last updated: June 24, 2025

In Derby, United States, the average temperature in September is a comfortable 23°C (74°F). However, be prepared for a range: temperatures can dip as low as 5°C (42°F) or soar up to 36°C (97°F). During this month, expect about 78 mm (3.1 in) of precipitation over 7 days, with an average humidity of 67%, creating a warm and slightly humid atmosphere.

September Temperature in Derby

In September in Derby, the average temperature is 23°C (74°F). Maximums can reach 36°C (97°F), and minimums can be as low as 5°C (42°F). Be prepared for warm days and cool nights while exploring this vibrant destination.

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

The chart illustrates September temperature patterns in Derby, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Derby, September typically has an average temperature of 23°C (74°F), with highs reaching up to 36°C (97°F) and lows dropping to around 5°C (42°F).

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

September Precipitation in Derby

In Derby in September, the total precipitation amount is 78 mm (3.1 in) over a duration of 7 days.

September Precipitation Trends in Derby

The chart displays monthly precipitation patterns in Derby, 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 Derby, September typically receives around 78 mm (3.1 inches) of precipitation spread over approximately 7 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 Derby

In Derby in September humidity is 67%. With an average temperature of 23°C (74°F), this humidity feels like a warm embrace, making outdoor exploration pleasant yet slightly sticky, perfect for leisurely strolls but requiring occasional breaks for hydration.

September Average Humidity in Derby

This chart illustrates the average monthly humidity levels in Derby, 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 Derby is approximately 67%, 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 Derby

In Derby 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 Derby.

Maximum UV Index Levels in Derby for September

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

Data source: Derby 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 Derby Compares to Other Months

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

This table compares monthly weather conditions in Derby, 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 (35°F)	40 mm (1.6 inches)	77%	moderate
February Weather	2°C (36°F)	28 mm (1.1 inches)	76%	high
March Weather	10°C (50°F)	82 mm (3.2 inches)	71%	high
April Weather	13°C (56°F)	85 mm (3.4 inches)	73%	very high
May Weather	19°C (67°F)	166 mm (6.5 inches)	83%	very high
June Weather	26°C (78°F)	106 mm (4.2 inches)	83%	extreme
July Weather	27°C (81°F)	67 mm (2.7 inches)	81%	extreme
August Weather	26°C (79°F)	86 mm (3.4 inches)	73%	very high
September Weather	23°C (74°F)	78 mm (3.1 inches)	67%	very high
October Weather	15°C (59°F)	127 mm (5.0 inches)	72%	high
November Weather	8°C (46°F)	27 mm (1.0 inches)	82%	moderate
December Weather	4°C (40°F)	30 mm (1.2 inches)	85%	moderate