September Weather in Johnstown, United States

Last updated: June 24, 2025

The average temperature in Johnstown, United States during September is a comfortable 19°C (66°F). However, temperatures can vary significantly, with a minimum of 0°C (32°F) and a maximum of 37°C (98°F). Expect 27 mm (1.1 in) of precipitation across 5 days, and enjoy an average humidity level of 63%.

September Temperature in Johnstown

In September in Johnstown, the average temperature is 19°C (66°F). Maximum temperatures can reach 37°C (98°F), while minimum temperatures can drop as low as 0°C (32°F). It’s advisable to pack accordingly to enjoy the diverse climate during your travels.

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

The chart illustrates September temperature patterns in Johnstown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Johnstown, September typically has an average temperature of 19°C (66°F), with highs reaching up to 37°C (98°F) and lows dropping to around 0°C (32°F).

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

September Precipitation in Johnstown

In Johnstown in September, the precipitation amount is 27 mm (1.1 in) over a period of 5 days.

September Precipitation Trends in Johnstown

The chart displays monthly precipitation patterns in Johnstown, 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 Johnstown, September typically receives around 27 mm (1.1 inches) of precipitation spread over approximately 5 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 Johnstown

In Johnstown in September, humidity is 63%. With an average temperature of 19°C (66°F), this humidity feels like a warm embrace, making it pleasantly comfortable for exploring the area's sights while infusing the air with a refreshing vitality that's ideal for travel.

September Average Humidity in Johnstown

This chart illustrates the average monthly humidity levels in Johnstown, 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 Johnstown is approximately 63%, 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 Johnstown

In Johnstown 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 Johnstown.

Maximum UV Index Levels in Johnstown for September

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

Data source: Johnstown 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 Johnstown Compares to Other Months

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

This table compares monthly weather conditions in Johnstown, 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 (30°F)	19 mm (0.8 inches)	84%	moderate
February Weather	-1°C (30°F)	26 mm (1.0 inches)	85%	high
March Weather	5°C (40°F)	56 mm (2.2 inches)	75%	very high
April Weather	9°C (48°F)	55 mm (2.2 inches)	67%	extreme
May Weather	13°C (56°F)	119 mm (4.7 inches)	67%	extreme
June Weather	20°C (69°F)	42 mm (1.6 inches)	68%	extreme
July Weather	23°C (75°F)	31 mm (1.2 inches)	62%	extreme
August Weather	22°C (73°F)	43 mm (1.7 inches)	63%	extreme
September Weather	19°C (66°F)	27 mm (1.1 inches)	63%	very high
October Weather	9°C (49°F)	38 mm (1.5 inches)	72%	high
November Weather	4°C (40°F)	23 mm (0.9 inches)	79%	moderate
December Weather	0°C (33°F)	15 mm (0.6 inches)	85%	moderate