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 Morden: The hottest months are usually August and July, with an average temperature of 18°C, while the coldest months are February and January, with an average of -11°C. The snowiest months in Morden are April, October, January and November, with each month seeing an average of 29 cm of snowfall.