Taking into account the local weather in Frantschach-Sankt Gertraud can help you maximize your time at the pool during your trip. The hottest months are usually July and August with an average temp of 59°F, while the coldest months are January and February with an average of 30°F. The rainiest months in Frantschach-Sankt Gertraud are July, June, August, and May, with each month seeing an average of 7 inches of rainfall.