About Morris Plains, NJ's Climate & Weather History

With a population of around 5,500, Morris Plains sits in New Jersey, United States. The city operates in the Eastern Time Zone.

In 2025, Morris Plains recorded an average annual temperature of 52°F — right at the 30-year normal of 53°F. The hottest day reached 97°F in June; the coldest was 3°F in January. Total precipitation was 44 inches (near normal). The wettest month was May.