Historical weather data, all-time temperature records, and monthly climate averages for Hopatcong, NJ. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Hopatcong typically sits in that awkward shoulder season sweet spot — expect a high around 55° and a low near 35°. The date has seen wild swings over 124 years of records, from a balmy 77° back in 1932 all the way down to a teeth-chattering 20° in 1896. There's a 40% chance of rain today, but snow is basically off the table at just 1%.
Hopatcong's weather has some serious range — 125 years of data stretches from a punishing 104° on September 3, 1953, to a brutal -21° on December 30, 1917, a swing of 125 degrees. On the wet side, a single day in July 1919 dumped 7.45 inches of rain, and the Blizzard of '96 buried the area under 22 inches of snow in one shot.
Summer is the clear star here, with highs peaking around 84-85° in mid-July and the wettest stretch of the year arriving right on its heels in late July, averaging over an inch of rain per week. If you're cold-averse, avoid late January through early February when highs scrape just 36°. Spring and fall offer a pleasant middle ground, with April climbing to 60° and October still holding at a comfortable 65°.