September Weather in Grayson, United States

Last updated: June 24, 2025

In September, the average temperature in Grayson, United States hovers around 21°C (71°F), making it a comfortable time to explore. However, be prepared for a range of temperatures, with minimums dipping to 7°C (45°F) and highs soaring up to 37°C (99°F). Rainfall is common, with an average precipitation of 113 mm (4.4 in) spread over 9 days, while the average humidity sits at a humid 73%. Ensure you pack accordingly for your visit!

September Temperature in Grayson

In September in Grayson, the average temperature is 21°C (71°F). Maximum temperatures can reach 37°C (99°F), while the minimum can drop to as low as 7°C (45°F). This makes it a perfect time for travelers to enjoy a variety of outdoor activities while being prepared for temperature fluctuations.

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

The chart illustrates September temperature patterns in Grayson, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grayson, September typically has an average temperature of 21°C (71°F), with highs reaching up to 37°C (99°F) and lows dropping to around 7°C (45°F).

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

September Precipitation in Grayson

In Grayson in September, the precipitation amount is 113 mm (4.4 in) over a period of 9 days.

September Precipitation Trends in Grayson

The chart displays monthly precipitation patterns in Grayson, 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 Grayson, September typically receives around 113 mm (4.4 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 Grayson

In Grayson in September humidity is 73%. With an average temperature of 21°C (71°F), this humidity feels like a warm, enveloping blanket that can make outdoor activities a bit uncomfortable, but with proper hydration and breaks in the shade, it’s still manageable for traveling.

September Average Humidity in Grayson

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

In Grayson 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 Grayson.

Maximum UV Index Levels in Grayson for September

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

Data source: Grayson 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 Grayson Compares to Other Months

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

This table compares monthly weather conditions in Grayson, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (36°F)	93 mm (3.7 inches)	88%	moderate
February Weather	5°C (41°F)	132 mm (5.2 inches)	88%	moderate
March Weather	9°C (48°F)	110 mm (4.3 inches)	87%	high
April Weather	13°C (56°F)	125 mm (4.9 inches)	85%	very high
May Weather	19°C (67°F)	130 mm (5.1 inches)	81%	very high
June Weather	23°C (73°F)	175 mm (6.9 inches)	82%	very high
July Weather	25°C (78°F)	118 mm (4.6 inches)	81%	very high
August Weather	24°C (75°F)	140 mm (5.5 inches)	73%	very high
September Weather	21°C (71°F)	113 mm (4.4 inches)	73%	very high
October Weather	16°C (60°F)	113 mm (4.4 inches)	78%	high
November Weather	7°C (46°F)	74 mm (2.9 inches)	89%	moderate
December Weather	5°C (41°F)	118 mm (4.6 inches)	87%	moderate