nomadseason

January Weather in Manassas, United States

Last updated: June 24, 2025

In January, the average temperature in Manassas, United States hovers around 3°C (37°F), but be prepared for a range that can dip to a brisk -15°C (5°F) or soar to a balmy 21°C (70°F). During the month, expect around 60 mm (2.4 in) of precipitation over 7 days, contributing to an average humidity level of 86%. Pack accordingly to enjoy all that this unique climate has to offer!

January Temperature in Manassas

In January in Manassas, the average temperature is 3°C (37°F), with maximums reaching up to 21°C (70°F) and minimums dipping as low as -15°C (5°F). Be sure to pack layers to stay comfortable during your travels!

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

The chart illustrates January temperature patterns in Manassas, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Manassas, January typically has an average temperature of 3°C (37°F), with highs reaching up to 21°C (70°F) and lows dropping to around -15°C (5°F).
JanFebMarAprMayJunJulAugSepOctNovDec374147576675817772624741
Data source: Temperature data for Manassas generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

January Precipitation in Manassas

In Manassas in January, the precipitation amount is 60 mm (2.4 in) over the course of 7 days.

January Precipitation Trends in Manassas

The chart displays monthly precipitation patterns in Manassas, 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 Manassas, January typically receives around 60 mm (2.4 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec609579103125108109146951088591
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

January Humidity in Manassas

In Manassas in January humidity is 86%. With an average temperature of 3°C (37°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities uncomfortable and travel less enjoyable.

January Average Humidity in Manassas

This chart illustrates the average monthly humidity levels in Manassas, 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 Manassas is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%86%86%84%78%79%70%59%68%80%87%85%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Manassas

In Manassas 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 Manassas, you can check the information here.

Maximum UV Index Levels in Manassas for January

The chart shows the monthly maximum UV Index (UVI) for Manassas 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 Manassas typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098753
Data source: Manassas 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 Manassas Compares to Other Months

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

This table compares monthly weather conditions in Manassas, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather3°C (37°F)60 mm (2.4 inches)86%moderate
February Weather5°C (41°F)95 mm (3.7 inches)86%moderate
March Weather8°C (47°F)79 mm (3.1 inches)86%high
April Weather14°C (57°F)102 mm (4.0 inches)84%very high
May Weather19°C (67°F)125 mm (4.9 inches)78%very high
June Weather24°C (75°F)108 mm (4.3 inches)79%very high
July Weather27°C (81°F)109 mm (4.3 inches)70%very high
August Weather25°C (78°F)146 mm (5.7 inches)59%very high
September Weather22°C (72°F)95 mm (3.7 inches)68%very high
October Weather17°C (62°F)108 mm (4.3 inches)80%high
November Weather8°C (47°F)85 mm (3.3 inches)86%moderate
December Weather5°C (41°F)90 mm (3.6 inches)85%moderate

Compare Manassas's Climate with Cities Worldwide