September Weather in Lambertville, United States

Last updated: June 24, 2025

In Lambertville, United States, the average temperature in September is a pleasant 20°C (68°F). However, temperatures can range widely, with a minimum of 4°C (40°F) and soaring up to 34°C (93°F). The month sees an average precipitation of 59 mm (2.3 in) spread over about 9 days, resulting in an overall average humidity of 78%. Enjoy the balance of warmth and occasional rain as you explore this vibrant locale!

September Temperature in Lambertville

In September in Lambertville, the average temperature is 20°C (68°F), with maximums reaching up to 34°C (93°F) and minimums dropping as low as 4°C (40°F). This variety in temperature makes it a great time for travelers to enjoy both outdoor activities and cozy indoor experiences.

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

The chart illustrates September temperature patterns in Lambertville, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Lambertville, September typically has an average temperature of 20°C (68°F), with highs reaching up to 34°C (93°F) and lows dropping to around 4°C (40°F).

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

September Precipitation in Lambertville

In Lambertville in September, the precipitation amount is 59 mm (2.3 in) over the course of 9 days.

September Precipitation Trends in Lambertville

The chart displays monthly precipitation patterns in Lambertville, 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 Lambertville, September typically receives around 59 mm (2.3 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 Lambertville

In Lambertville in September humidity is 78%. With an average temperature of 20°C (68°F), this humidity feels like a warm, enveloping blanket that makes exploring the sights a bit sticky, so travelers should stay hydrated and take frequent breaks in the shade.

September Average Humidity in Lambertville

This chart illustrates the average monthly humidity levels in Lambertville, 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 Lambertville is approximately 78%, 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 Lambertville

In Lambertville 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 Lambertville.

Maximum UV Index Levels in Lambertville for September

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

Data source: Lambertville 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 Lambertville Compares to Other Months

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

This table compares monthly weather conditions in Lambertville, 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 (28°F)	67 mm (2.6 inches)	88%	moderate
February Weather	-2°C (29°F)	68 mm (2.7 inches)	87%	moderate
March Weather	4°C (39°F)	81 mm (3.2 inches)	87%	high
April Weather	9°C (49°F)	89 mm (3.5 inches)	87%	very high
May Weather	16°C (61°F)	136 mm (5.4 inches)	81%	very high
June Weather	22°C (71°F)	97 mm (3.8 inches)	82%	very high
July Weather	24°C (76°F)	107 mm (4.2 inches)	81%	very high
August Weather	23°C (74°F)	84 mm (3.3 inches)	78%	very high
September Weather	20°C (68°F)	59 mm (2.3 inches)	78%	very high
October Weather	13°C (56°F)	93 mm (3.7 inches)	82%	high
November Weather	5°C (41°F)	82 mm (3.2 inches)	89%	moderate
December Weather	1°C (34°F)	54 mm (2.1 inches)	86%	low