Historical weather data, all-time temperature records, and monthly climate averages for Fullerton, PA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Fullerton runs mild but unpredictable — the average high of 57° masks a 60-degree swing in the historical record, from a bitter 21° in 1995 to a shirt-sleeve 81° in 1985. Snow is nearly off the table at just a 1% chance, but there's still a 1-in-3 shot at rain. Expect a classic mid-spring tease.
Fullerton has seen genuine extremes over its 78 years of records — a punishing 105° on July 3, 1966 and a brutal -15° on January 21, 1994, a 120-degree spread that captures the full fury of mid-Atlantic climate. A single October storm in 2005 dumped 8.71 inches of rain, and the January 2016 blizzard buried the area under 30.2 inches of snow in one shot.
Summer is the clear headliner, with highs peaking around 85-86° in mid-July and staying in the 80s through August. If you're avoiding heat, January and February are the coldest months, with average highs barely cracking the mid-30s to 40°. Wettest conditions arrive in early August, so late spring and early fall are your best bets for comfortable, drier weather.