Planning for the weather is an important factor for making your trip to Port Jervis a success, especially when you’re splurging. The hottest months are usually July and August, with an average temperature of 20°C, while the coldest months are January and February, with an average of -1°C. The snowiest months in Port Jervis are February, January, March and November, with each month seeing an average of 23 cm of snowfall.