March Weather in Fullerton, United States

Last updated: June 24, 2025

In March, the average temperature in Fullerton, United States hovers around 4°C (40°F). Be prepared for a range of weather, with minimums dipping to -21°C (-5°F) and peaking at a pleasant 26°C (79°F). During this month, you can expect an average precipitation of 89 mm (3.5 in) spread over 9 days, along with an average humidity level of 69%. Stay cozy and plan accordingly!

March Temperature in Fullerton

In March in Fullerton, the average temperature is 4°C (40°F). The maximum can reach 26°C (79°F), while the minimum can be as low as -21°C (-5°F). Be prepared for a wide range of temperatures when planning your travel to Fullerton this month!

March Weather in Fullerton: Daily Temperature Highs, Lows, and Averages

The chart illustrates March temperature patterns in Fullerton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fullerton, March typically has an average temperature of 4°C (40°F), with highs reaching up to 26°C (79°F) and lows dropping to around -21°C (-5°F).

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

March Precipitation in Fullerton

In Fullerton in March, the precipitation amount is 89 mm (3.5 in) during a span of 9 days.

March Precipitation Trends in Fullerton

The chart displays monthly precipitation patterns in Fullerton, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In Fullerton, March typically receives around 89 mm (3.5 inches) of precipitation spread over approximately 9 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

March Humidity in Fullerton

In Fullerton in March, humidity is 69%. With an average temperature of 4°C (40°F), this humidity feels like a brisk chill that penetrates your layers, making traveling outdoors somewhat uncomfortable as the cold air combines with the dampness, creating a biting sensation that can quickly sap your warmth.

March Average Humidity in Fullerton

This chart illustrates the average monthly humidity levels in Fullerton, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in Fullerton is approximately 69%, offering insight into how humid the weather typically is during this month.

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

March UV Index in Fullerton

In Fullerton in March, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Fullerton, you can refer to this Hourly UV Index in Fullerton.

Maximum UV Index Levels in Fullerton for March

The chart shows the monthly maximum UV Index (UVI) for Fullerton in March, 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 March, the maximum UV index in Fullerton typically reaches 6, which falls under the high exposure category.

Data source: Fullerton March 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 March Weather in Fullerton Compares to Other Months

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

This table compares monthly weather conditions in Fullerton, showing how March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (26°F)	28 mm (1.1 inches)	73%	moderate
February Weather	-4°C (25°F)	20 mm (0.8 inches)	81%	moderate
March Weather	4°C (40°F)	89 mm (3.5 inches)	69%	high
April Weather	9°C (49°F)	57 mm (2.2 inches)	71%	very high
May Weather	16°C (61°F)	142 mm (5.6 inches)	80%	very high
June Weather	24°C (75°F)	97 mm (3.8 inches)	83%	extreme
July Weather	25°C (78°F)	65 mm (2.5 inches)	84%	very high
August Weather	23°C (74°F)	84 mm (3.3 inches)	84%	very high
September Weather	20°C (69°F)	57 mm (2.2 inches)	77%	very high
October Weather	11°C (52°F)	83 mm (3.3 inches)	72%	high
November Weather	4°C (40°F)	22 mm (0.9 inches)	80%	moderate
December Weather	-1°C (31°F)	42 mm (1.6 inches)	79%	moderate