If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Mwanza: The hottest months are usually February and July with an average temp of 74°F, while the coldest months are July and May with an average of 73°F. The rainiest months in Mwanza are November, April, December, and October, with each month seeing an average of 10 inches of rainfall.