September Weather in Nikiski, United States

Last updated: June 24, 2025

In September, the average temperature in Nikiski, United States reaches a cool 11°C (53°F). Expect to see a minimum of 4°C (40°F) and a maximum of 17°C (63°F) during this time. Rainfall is quite substantial, with 137 mm (5.4 in) of precipitation spread over 17 days. Additionally, the air tends to be quite humid, averaging around 97%.

September Temperature in Nikiski

In September in Nikiski, the average temperature is 11°C (53°F). Maximums can reach 17°C (63°F), while minimums can drop as low as 4°C (40°F). It's a great time to explore Nikiski with mild weather, so pack accordingly for both warm and cool moments.

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

The chart illustrates September temperature patterns in Nikiski, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Nikiski, September typically has an average temperature of 11°C (53°F), with highs reaching up to 17°C (63°F) and lows dropping to around 4°C (40°F).

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

September Precipitation in Nikiski

In Nikiski in September, the total precipitation amount is 137 mm (5.4 in), occurring over a span of 17 days.

September Precipitation Trends in Nikiski

The chart displays monthly precipitation patterns in Nikiski, 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 Nikiski, September typically receives around 137 mm (5.4 inches) of precipitation spread over approximately 17 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 Nikiski

In Nikiski in September, humidity is 97%. With an average temperature of 11°C (53°F), this humidity feels like a damp blanket enveloping you, making travel uncomfortable as the air feels heavy and your clothes cling uncomfortably to your skin.

September Average Humidity in Nikiski

This chart illustrates the average monthly humidity levels in Nikiski, 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 Nikiski is approximately 97%, 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 Nikiski

In Nikiski in September, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Nikiski for better planning.

Maximum UV Index Levels in Nikiski for September

The chart shows the monthly maximum UV Index (UVI) for Nikiski 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 Nikiski typically reaches 4, which falls under the moderate exposure category.

Data source: Nikiski 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 Nikiski Compares to Other Months

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

This table compares monthly weather conditions in Nikiski, 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 (25°F)	53 mm (2.1 inches)	95%	low
February Weather	-3°C (27°F)	59 mm (2.3 inches)	95%	low
March Weather	-2°C (29°F)	41 mm (1.6 inches)	90%	low
April Weather	2°C (36°F)	39 mm (1.6 inches)	82%	moderate
May Weather	7°C (44°F)	63 mm (2.5 inches)	85%	moderate
June Weather	11°C (52°F)	43 mm (1.7 inches)	95%	high
July Weather	14°C (57°F)	77 mm (3.0 inches)	100%	high
August Weather	14°C (58°F)	97 mm (3.8 inches)	99%	moderate
September Weather	11°C (53°F)	137 mm (5.4 inches)	97%	moderate
October Weather	6°C (44°F)	150 mm (5.9 inches)	93%	low
November Weather	0°C (32°F)	101 mm (4.0 inches)	97%	low
December Weather	-2°C (29°F)	109 mm (4.3 inches)	98%	low