January Weather in Iselin, United States

Last updated: June 24, 2025

In January, the average temperature in Iselin, United States hovers around 1°C (35°F), with a range that can dip to a chilly -18°C (0°F) and peak at a mild 19°C (66°F). Expect about 66 mm (2.6 in) of precipitation spread over 8 days, contributing to an average humidity of 84%. Stay prepared for the variable weather!

January Temperature in Iselin

In January in Iselin, the average temperature is 1°C (35°F), with maximums reaching 19°C (66°F) and minimums dropping as low as -18°C (0°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

January Weather in Iselin: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Iselin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iselin, January typically has an average temperature of 1°C (35°F), with highs reaching up to 19°C (66°F) and lows dropping to around -18°C (0°F).

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

January Precipitation in Iselin

In Iselin in January, the total precipitation amount is 66 mm (2.6 in) over the course of 8 days.

January Precipitation Trends in Iselin

The chart displays monthly precipitation patterns in Iselin, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Iselin, January typically receives around 66 mm (2.6 inches) of precipitation spread over approximately 8 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Iselin

In Iselin in January humidity is 84%. With an average temperature of 1°C (35°F), this humidity feels like a cold, damp chill that seeps into your bones, making it feel much colder than the thermometer suggests, which can be quite uncomfortable for traveling.

January Average Humidity in Iselin

This chart illustrates the average monthly humidity levels in Iselin, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Iselin is approximately 84%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Iselin

In Iselin in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Iselin, you can check the information here.

Maximum UV Index Levels in Iselin for January

The chart shows the monthly maximum UV Index (UVI) for Iselin in January, 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 January, the maximum UV index in Iselin typically reaches 3, which falls under the moderate exposure category.

Data source: Iselin January 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 January Weather in Iselin Compares to Other Months

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

This table compares monthly weather conditions in Iselin, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (35°F)	66 mm (2.6 inches)	84%	moderate
February Weather	3°C (37°F)	107 mm (4.2 inches)	82%	moderate
March Weather	6°C (43°F)	103 mm (4.0 inches)	81%	high
April Weather	12°C (53°F)	111 mm (4.4 inches)	78%	very high
May Weather	17°C (63°F)	118 mm (4.6 inches)	69%	very high
June Weather	22°C (73°F)	94 mm (3.7 inches)	69%	very high
July Weather	26°C (79°F)	144 mm (5.6 inches)	62%	very high
August Weather	25°C (77°F)	126 mm (5.0 inches)	65%	very high
September Weather	21°C (71°F)	91 mm (3.6 inches)	68%	very high
October Weather	16°C (61°F)	130 mm (5.1 inches)	74%	high
November Weather	8°C (47°F)	82 mm (3.2 inches)	82%	moderate
December Weather	4°C (39°F)	102 mm (4.0 inches)	80%	low