September Weather in Grafton, United States

Last updated: June 24, 2025

In September, the average temperature in Grafton, United States hovers around 15°C (59°F). While temperatures can dip as low as -2°C (29°F), they can also soar to a maximum of 33°C (92°F). Visitors can expect 82 mm (3.2 in) of precipitation spread over 8 days, with an average humidity of 73%—ideal for those who enjoy a pleasantly moist climate!

September Temperature in Grafton

In September in Grafton, the average temperature is 15°C (59°F), with maximums reaching 33°C (92°F) and minimums dropping as low as -2°C (29°F). This wide range of temperatures makes Grafton an exciting destination for travelers looking to experience diverse weather conditions.

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

The chart illustrates September temperature patterns in Grafton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grafton, September typically has an average temperature of 15°C (59°F), with highs reaching up to 33°C (92°F) and lows dropping to around -2°C (29°F).

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

September Precipitation in Grafton

In Grafton in September, the total precipitation amount reached 82 mm (3.2 in) over the course of 8 days.

September Precipitation Trends in Grafton

The chart displays monthly precipitation patterns in Grafton, 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 Grafton, September typically receives around 82 mm (3.2 inches) of precipitation spread over approximately 8 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 Grafton

In Grafton in September humidity is 73%. With an average temperature of 15°C (59°F), this humidity feels like a mild discomfort, making sightseeing a bit sticky and requiring travelers to stay hydrated and take breaks in the shade.

September Average Humidity in Grafton

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

In Grafton in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Grafton.

Maximum UV Index Levels in Grafton for September

The chart shows the monthly maximum UV Index (UVI) for Grafton 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 Grafton typically reaches 7, which falls under the high exposure category.

Data source: Grafton 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 Grafton Compares to Other Months

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

This table compares monthly weather conditions in Grafton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-13°C (9°F)	17 mm (0.6 inches)	92%	low
February Weather	-14°C (7°F)	18 mm (0.7 inches)	90%	moderate
March Weather	-4°C (25°F)	22 mm (0.9 inches)	88%	moderate
April Weather	3°C (38°F)	27 mm (1.1 inches)	81%	high
May Weather	13°C (55°F)	48 mm (1.9 inches)	74%	very high
June Weather	20°C (68°F)	64 mm (2.5 inches)	72%	very high
July Weather	22°C (72°F)	54 mm (2.1 inches)	74%	very high
August Weather	20°C (68°F)	63 mm (2.5 inches)	76%	very high
September Weather	15°C (59°F)	82 mm (3.2 inches)	73%	high
October Weather	6°C (43°F)	79 mm (3.1 inches)	76%	moderate
November Weather	-3°C (26°F)	26 mm (1.0 inches)	86%	moderate
December Weather	-9°C (16°F)	30 mm (1.2 inches)	91%	low