If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Seward: The hottest months are usually July and August, with an average temperature of 11°C, while the coldest months are March and January, with an average of -3°C. The snowiest months in Seward are December, January, February and March, with each month seeing an average of 159 cm of snowfall.