You'll likely spend much of your trip indoors, but if you're planning to venture beyond the casino, looking at local weather trends is a good idea. The hottest months are usually July and August, with an average temperature of 14°C, while the coldest months are January and February, with an average of -2°C. The rainiest months in Chamoson are May, July, December and August, with each month seeing an average of 187 mm of rainfall.