Taking the local weather in Altenrhein into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually July and August, with an average temperature of 17°C, while the coldest months are January and February, with an average of 1°C. The rainiest months in Altenrhein are August, June, July and May, with each month seeing an average of 183 mm of rainfall.