Historical weather data, all-time temperature records, and monthly climate averages for Norristown, PA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5 in Norristown sits right in that shoulder-season sweet spot — historically averaging a 60° high and 38° low, but don't get too comfortable. This date has swung from a balmy 78° back in 1981 all the way down to a brutal 22° in 2001, and there's nearly a coin-flip chance of rain.
Norristown plays for keeps on both ends of the thermometer. The mercury has soared to a scorching 108° (July 2011) and plunged to a bone-chilling -12° (January 1982) — a 120-degree spread that tells you this is a place with real seasons. October 2001 added a drenching 7" in a single day, while a February 2006 storm buried the area under 18" of snow.
Summer is the main event in Norristown, with highs peaking around 88-89° in mid-to-late July and the wettest stretch of the year arriving at the end of that same month. Winter bottoms out mid-January with average highs barely cracking 39°. Spring and fall offer a pleasant middle ground, though April still carries a healthy dose of uncertainty.