January Weather in Pomona, United States

Last updated: June 24, 2025

In Pomona, United States, the average temperature in January hovers around 0°C (33°F). Here, you can experience a significant temperature range, with minimums dropping to -21°C (-6°F) and maximums reaching up to 19°C (66°F). Expect 53 mm (2.1 in) of precipitation spread over about 5 days, contributing to an average humidity level of 76%.

January Temperature in Pomona

In January in Pomona, the average temperature is 0°C (33°F). The maximum can reach 19°C (66°F), and the minimum can be as low as -21°C (-6°F). Be prepared for a wide range of temperatures, making layered clothing essential for your visit.

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

The chart illustrates January temperature patterns in Pomona, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Pomona, January typically has an average temperature of 0°C (33°F), with highs reaching up to 19°C (66°F) and lows dropping to around -21°C (-6°F).

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

January Precipitation in Pomona

In Pomona in January, the precipitation amount is 53 mm (2.1 in) during a span of 5 days.

January Precipitation Trends in Pomona

The chart displays monthly precipitation patterns in Pomona, 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 Pomona, January typically receives around 53 mm (2.1 inches) of precipitation spread over approximately 5 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 Pomona

In Pomona in January, humidity is 76%. With an average temperature of 0°C (33°F), this humidity feels like a damp chill that seeps through your layers, making travel uncomfortable and urging you to seek out cozy indoor spaces.

January Average Humidity in Pomona

This chart illustrates the average monthly humidity levels in Pomona, 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 Pomona is approximately 76%, 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 Pomona

In Pomona 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 Pomona, you can check the information here.

Maximum UV Index Levels in Pomona for January

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

Data source: Pomona 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 Pomona Compares to Other Months

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

This table compares monthly weather conditions in Pomona, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	0°C (33°F)	53 mm (2.1 inches)	76%	moderate
February Weather	1°C (34°F)	35 mm (1.4 inches)	77%	high
March Weather	9°C (48°F)	95 mm (3.7 inches)	70%	high
April Weather	13°C (55°F)	94 mm (3.7 inches)	73%	very high
May Weather	19°C (66°F)	202 mm (7.9 inches)	82%	very high
June Weather	25°C (78°F)	111 mm (4.4 inches)	82%	extreme
July Weather	27°C (80°F)	105 mm (4.1 inches)	81%	extreme
August Weather	25°C (77°F)	121 mm (4.8 inches)	78%	very high
September Weather	22°C (72°F)	80 mm (3.1 inches)	71%	very high
October Weather	14°C (58°F)	118 mm (4.6 inches)	71%	high
November Weather	7°C (45°F)	38 mm (1.5 inches)	81%	moderate
December Weather	4°C (39°F)	32 mm (1.3 inches)	84%	moderate