Taking into account the local weather in Brig is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually July and August with an average temp of 47°F, while the coldest months are January and February with an average of 18°F. The rainiest months in Brig are July, August, June, and May, with each month seeing an average of 7 inches of rainfall.