According to the Köppen climate classification system, Towamencin is located in zone Dfa, indicating a humid continental climate with hot summers. Its USDA plant hardiness zone is 6b, except in some lower areas where it is 7a. The warmest month is typically July, with an average maximum temperature of 85.7 °F (29.8 °C). Between 1895 and 2019, the average July maximum temperature never fell below 81 °F (27 °C), and rose above 90 °F (32 °C) in 1955, 1999, and 2011. Over the same period, the January mean temperature ranged from 19.3 °F (−7 °C) in 1918 and 1977 to a peak of 42 °F (5.5 °C) in 1932. January 1918 also recorded the lowest average maximum temperature, at 27.5 °F (−2.5 °C). The typical January has a daily mean temperature of 31 °F (−0.5 °C). The mean temperature in July is 76 °F (24 °C). The hot season lasts from late May through mid-September, while the cold season typically runs from December through early March. The highest recorded temperature in the township was 103.2 °F (39.6 °C) in 2011, and the lowest recorded temperature was −10.7 °F (−23.7 °C) in 1984.
