NWS, American, European side by side around Fullerton and nearby towns.Live rain radar →
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Next 14 hours
consensus of the three models
7-day forecast
where the models agree, and where they split
Fullerton, CA is at its warmest in Jul (average highs near 86°F) and coldest in Jan (lows around 46°F), with roughly 27 in of precipitation across the year. Below, compare what NWS, American, European forecast for Fullerton right now, and see exactly where they disagree.
Fullerton climate by month
average daytime high and overnight low across a typical year
Jan
63°
46°
Feb
63°
46°
Mar
63°
48°
Apr
71°
51°
May
71°
54°
Jun
77°
59°
Jul
86°
63°
Aug
86°
64°
Sep
83°
63°
Oct
82°
58°
Nov
74°
53°
Dec
69°
51°
Common questions
What's the weather in Fullerton today?
On this page we show what NWS, American, European each forecast for Fullerton today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Fullerton today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Fullerton and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Fullerton?
No single model is always right. NWS, American, European each run their own physics, so we line all three up: when they agree the Fullerton forecast is reliable, and when they split you should expect surprises. See our tested US accuracy scoreboard for how the models compare.
What is the warmest month in Fullerton?
Jul is typically the warmest month in Fullerton, with average highs around 86°F.
How cold does Fullerton get?
The coldest month in Fullerton is Jan, when overnight lows average about 46°F.
How much rain does Fullerton get?
Fullerton sees roughly 27 in of precipitation a year, with Feb usually the wettest month.
The forecasts Americans check
The two biggest apps keep their model a secret, so we can't show their numbers, only link you to them. The National Weather Service is public, so its data sits right in the comparison above.