September Weather in Plano, United States

Last updated: June 24, 2025

In September, the average temperature in Plano, United States hovers around 23°C (73°F), making it a pleasant time to visit. However, temperatures can fluctuate, with a minimum of 8°C (47°F) and a sweltering maximum of 37°C (99°F). Visitors should also prepare for some rain, as the area experiences an average precipitation of 132 mm (5.2 in) over 9 days. With an average humidity level of 71%, the weather can feel quite warm and sticky, so stay hydrated!

September Temperature in Plano

In September in Plano, the average temperature is 23°C (73°F), with maximums reaching 37°C (99°F) and minimums dropping as low as 8°C (47°F). This makes it an ideal time for travelers seeking pleasant weather along with a variety of temperatures for different activities.

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

The chart illustrates September temperature patterns in Plano, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Plano, September typically has an average temperature of 23°C (73°F), with highs reaching up to 37°C (99°F) and lows dropping to around 8°C (47°F).

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

September Precipitation in Plano

In Plano in September, the total precipitation amount is 132 mm (5.2 in) over a span of 9 days.

September Precipitation Trends in Plano

The chart displays monthly precipitation patterns in Plano, 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 Plano, September typically receives around 132 mm (5.2 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 Plano

In Plano in September humidity is 71%. With an average temperature of 23°C (73°F), this humidity feels like a warm, sticky embrace, making outdoor exploration slightly uncomfortable but still manageable if you stay hydrated and plan for breaks in shaded areas.

September Average Humidity in Plano

This chart illustrates the average monthly humidity levels in Plano, 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 Plano is approximately 71%, 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 Plano

In Plano 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 Plano.

Maximum UV Index Levels in Plano for September

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

Data source: Plano 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 Plano Compares to Other Months

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

This table compares monthly weather conditions in Plano, 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 (39°F)	97 mm (3.8 inches)	87%	moderate
February Weather	6°C (43°F)	178 mm (7.0 inches)	86%	high
March Weather	10°C (51°F)	139 mm (5.5 inches)	86%	high
April Weather	14°C (58°F)	159 mm (6.3 inches)	82%	very high
May Weather	21°C (70°F)	121 mm (4.8 inches)	82%	very high
June Weather	25°C (76°F)	153 mm (6.0 inches)	83%	extreme
July Weather	27°C (80°F)	121 mm (4.8 inches)	80%	extreme
August Weather	25°C (78°F)	135 mm (5.3 inches)	74%	very high
September Weather	23°C (73°F)	132 mm (5.2 inches)	71%	very high
October Weather	17°C (62°F)	126 mm (5.0 inches)	78%	high
November Weather	8°C (47°F)	87 mm (3.4 inches)	88%	moderate
December Weather	6°C (44°F)	132 mm (5.2 inches)	88%	moderate