If you're looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Formosa: The hottest months are usually January and February, with an average temperature of 27°C, while the coldest months are July and June, with an average of 18°C. The snowiest months in Formosa are May, January, February and March, with each month seeing an average of 17 cm of snowfall.