Hottest and Coldest Temperatures Ever in Allentown on September 17

On September 17th in Allentown, the highest recorded temperature was 93.0°F in 1991, while the lowest recorded temperature was 39.0°F in 1959. The average temperature for this date is 64.87°F, with an average high of 70.08°F and an average low of 59.65°F. In 1991, during the same time when Allentown experienced its hottest temperature, the world's first website went live, marking a significant milestone in the history of the internet.