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September Weather in Grayson, United States

Last updated: June 24, 2025

In September, the average temperature in Grayson, United States is a warm 26°C (80°F). Expect a broad range, with minimums dipping to 12°C (54°F) and maximums soaring up to 40°C (104°F). Be prepared for some rain, as the area receives an average precipitation of 96 mm (3.8 in) over 8 days, accompanied by a high humidity level of 79%.

September Temperature in Grayson

In September in Grayson, the average temperature is 26°C (80°F). Maximums can reach 40°C (104°F), and minimums can be as low as 12°C (54°F). Travelers should be prepared for warm days and cooler nights, so packing versatile clothing is essential.

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 26°C (80°F), with highs reaching up to 40°C (104°F) and lows dropping to around 12°C (54°F).
JanFebMarAprMayJunJulAugSepOctNovDec495362667580828279695653
Data source: Temperature data for Grayson generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Grayson

In Grayson in September, the precipitation amount is 96 mm (3.8 in) over the course of 8 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 96 mm (3.8 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec1131691141401441311131209612080124
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Grayson

In Grayson in September, humidity is 79%. With an average temperature of 26°C (80°F), this humidity feels like an enveloping warm blanket, making travel feel slightly sluggish and prompting frequent hydration breaks to stay comfortable while exploring the sights.

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 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec83%83%80%81%81%78%79%79%79%77%85%88%
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 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 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 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec479111112121110864
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.
 TemperaturePrecipitationHumidityUV
January Weather10°C (49°F)112 mm (4.4 inches)83%moderate
February Weather12°C (54°F)169 mm (6.6 inches)83%high
March Weather17°C (62°F)114 mm (4.5 inches)80%very high
April Weather19°C (66°F)140 mm (5.5 inches)81%extreme
May Weather24°C (75°F)144 mm (5.7 inches)81%extreme
June Weather27°C (80°F)131 mm (5.1 inches)78%extreme
July Weather28°C (83°F)113 mm (4.4 inches)79%extreme
August Weather28°C (83°F)120 mm (4.7 inches)79%extreme
September Weather26°C (80°F)96 mm (3.8 inches)79%very high
October Weather21°C (70°F)120 mm (4.7 inches)77%very high
November Weather13°C (56°F)80 mm (3.2 inches)85%high
December Weather12°C (53°F)124 mm (4.9 inches)88%moderate

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