If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in South Amboy: The hottest months are usually July and August, with an average temperature of 23°C, while the coldest months are January and February, with an average of 3°C. The snowiest months in South Amboy are February, January, March and April, with each month seeing an average of 13 cm of snowfall.