If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Murwillumbah: The hottest months are usually January and February with an average temp of 74°F, while the coldest months are July and August with an average of 62°F. The rainiest months in Murwillumbah are January, February, March, and December, with each month seeing an average of 7 inches of rainfall.