Taking into account the local weather in Inverarnan 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 53°F, while the coldest months are January and February with an average of 36°F. The rainiest months in Inverarnan are October, December, November, and January, with each month seeing an average of 8 inches of rainfall.