Fontana, California, United States climate

Average temperatures, precipitation and all-time records for Fontana, California, United States, with every day graded against ~46 years of local climate history (1980–2026). Its warmest month is August, averaging a high of 91°F, and its coldest is December, with an average low of 42°F.

Fontana is a city in San Bernardino County, California, United States. Founded by Azariel Blanchard Miller in 1913, it remained essentially rural until World War II, when entrepreneur Henry J. Kaiser built a large steel mill in the area. via Wikipedia

How today compares

Latest recorded day: 2026-07-24. Each reading placed on Fontana, California, United States's own ±7-day seasonal distribution.

High 102°F Very High · 98th pct

Low 74°F Very High · 97th pct

Feels-like 106°F High · 75th pct

Humidity 13.3 g/m³ Normal · 49th pct

Wind 14 mph Near Record · 99th pct

Gust 19 mph Normal · 43rd pct

Precip 0.00 in Dry

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Fontana average temperatures by month

Typical daily high and low, and average precipitation, for each month in Fontana, California, United States, based on 1980–2026 records. The wettest month is February (0.20 in on an average day).

Month	Avg high	Avg low	Avg precip
January	64°F	43°F	0.10 in
February	65°F	44°F	0.20 in
March	69°F	47°F	0.10 in
April	73°F	50°F	0.10 in
May	77°F	55°F	0.00 in
June	84°F	60°F	0.00 in
July	91°F	66°F	0.00 in
August	91°F	67°F	0.00 in
September	87°F	63°F	0.00 in
October	81°F	56°F	0.00 in
November	71°F	48°F	0.10 in
December	64°F	42°F	0.10 in

Jan 35°–74°

Feb 37°–77°

Mar 40°–80°

Apr 44°–85°

May 49°–89°

Jun 55°–94°

Jul 61°–97°

Aug 61°–99°

Sep 57°–97°

Oct 50°–91°

Nov 41°–81°

Dec 35°–73°

Each bar spans the 10th-percentile daily low to the 90th-percentile daily high (the range most days fall within), coloured cold → hot on a shared -10°F to 115°F scale, so the whole year's rhythm reads at a glance.

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Record extremes

Hottest day on record: 115°F on 2020-09-06
Coldest day on record: 25°F on 1990-12-23

All Fontana weather records →

Percentiles compare each day to Fontana, California, United States's own history, so grades are relative to this location: a “Near Record” day here isn't the same temperature as elsewhere. How the grades work →