If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Sitka: The hottest months are usually August and July, with an average temperature of 12°C, while the coldest months are February and March, with an average of 0°C. The snowiest months in Sitka are February, December, January and March, with each month seeing an average of 25 cm of snowfall.