Climate

Fontana weather by month

Average highs, lows, rain and snow for every month, from 30 years of weather records.

Average temperatures

Best time to visit: April, May, October, when highs are mild and rain is lightest.

Month	High	Low	Rain	Wet days
January	68°F	44°F	2.3 in	5
February	68°F	45°F	2.4 in	7
March	72°F	47°F	1.2 in	5
April	76°F	50°F	0.60 in	4
May	80°F	55°F	0.20 in	2
June	87°F	59°F	0.00 in	0
July	93°F	64°F	0.10 in	1
August	95°F	65°F	0.00 in	1
September	91°F	62°F	0.10 in	1
October	83°F	55°F	0.30 in	2
November	75°F	47°F	0.60 in	4
December	67°F	43°F	1.5 in	5

NOAA U.S. Climate Normals 1991–2020, Riverside Muni Ap, Ca Us (9.7 mi away, 805 ft). Wet days: days with at least 0.01 in of precipitation.

What is the hottest month in Fontana?

August, with an average high of 95°F and low of 65°F.

What is the coldest month in Fontana?

December, with an average low of 43°F and high of 67°F.

When does it rain most in Fontana?

February is the wettest month, averaging 2.4 in of precipitation; the year totals about 9.3 inches.

What is the best time to visit Fontana?

For mild weather (highs between 65°F and 85°F) with the least rain, April, May, October.

Where do these numbers come from?

NOAA’s 1991–2020 U.S. Climate Normals for the Riverside Muni Ap weather station, 9.7 miles from downtown: 30-year averages, not a forecast.