January Weather in Rosslyn, United States

Last updated: June 24, 2025

In January, the average temperature in Rosslyn, United States hovers around 3°C (37°F). While temperatures can dip to a chilly -15°C (5°F), they can also rise to a pleasant 22°C (71°F). Expect about 61 mm (2.4 in) of precipitation spread over 8 days, accompanied by an average humidity of 84%.

January Temperature in Rosslyn

In January in Rosslyn, the average temperature is 3°C (37°F), with maximums reaching up to 22°C (71°F) and minimums dropping as low as -15°C (5°F). Be prepared for a wide range of temperatures, making layers essential for a comfortable trip.

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

The chart illustrates January temperature patterns in Rosslyn, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rosslyn, January typically has an average temperature of 3°C (37°F), with highs reaching up to 22°C (71°F) and lows dropping to around -15°C (5°F).

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

January Precipitation in Rosslyn

In Rosslyn in January, the precipitation amount is 61 mm (2.4 in) distributed over 8 days.

January Precipitation Trends in Rosslyn

The chart displays monthly precipitation patterns in Rosslyn, 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 Rosslyn, January typically receives around 61 mm (2.4 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 Rosslyn

In Rosslyn in January humidity is 84%. With an average temperature of 3°C (37°F), this humidity feels like a damp chill that seeps into your bones, making outdoor excursions brisk and invigorating, yet requiring extra layers to stay comfortable.

January Average Humidity in Rosslyn

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

In Rosslyn 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 Rosslyn, you can check the information here.

Maximum UV Index Levels in Rosslyn for January

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

Data source: Rosslyn 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 Rosslyn Compares to Other Months

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

This table compares monthly weather conditions in Rosslyn, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	3°C (37°F)	61 mm (2.4 inches)	84%	moderate
February Weather	5°C (41°F)	98 mm (3.9 inches)	83%	moderate
March Weather	8°C (46°F)	87 mm (3.4 inches)	83%	high
April Weather	14°C (57°F)	100 mm (4.0 inches)	81%	very high
May Weather	19°C (66°F)	127 mm (5.0 inches)	78%	very high
June Weather	24°C (75°F)	118 mm (4.7 inches)	79%	very high
July Weather	27°C (81°F)	157 mm (6.2 inches)	74%	very high
August Weather	25°C (77°F)	140 mm (5.5 inches)	72%	very high
September Weather	22°C (72°F)	95 mm (3.8 inches)	75%	very high
October Weather	17°C (62°F)	104 mm (4.1 inches)	81%	high
November Weather	8°C (47°F)	81 mm (3.2 inches)	85%	moderate
December Weather	5°C (41°F)	93 mm (3.7 inches)	84%	moderate