Historical weather data, all-time temperature records, and monthly climate averages for Horsham, PA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Horsham lands in that classic mid-spring swing — expect a high near 59° and a low around 41°, with roughly a 1-in-3 chance of rain. The date has seen everything from a balmy 79° back in 2017 to a brutal 21° in 1962, so the range is real.
Horsham has seen the full extremes of the mid-Atlantic — from a scorching 105° in July 2011 to a bone-chilling -6° in January 1982, a spread of 111 degrees. The wettest single day on record dumped 6.32 inches in September 1999, a reminder that late-summer storms can be no joke here.
Summer is the main event in Horsham, with highs peaking around 88° in late July and the wettest stretch of the year arriving right on summer's heels. If you're planning a visit, May through June hits the sweet spot — warm but not oppressive, with average highs in the 70s and 80s. Winter runs cold but short, with the coolest week of the year averaging just 38° in mid-January before temps start climbing again by March.