Graz is the second largest and one of the most important tourist destinations of Austria. The weather here can be classified to be warm summer continental kinds with influences from the Mediterranean and gets shielded from extreme winds by the Alps. The average annual temperature is around 8 – 9 degree Celsius and rainfall is majorly experienced in the summer months.
Winter: Winter usually lasts from November to February and the average temperature during these months is somewhere around 0 to -2 degree Celsius. Precipitation levels are quite low during these months.
Spring: March to May is the spring season and the temperatures are usually around 8 degree Celsius during these months. Rainfall levels see a gradual increase in frequency. This is the peak tourist season.
Summer: June to August sees temperatures of around 17 degree Celsius and very high amounts of rainfall. The weather can be a little humid at times, but is pleasant generally.
Autumn: September to October sees a decline in the precipitation levels and also in the mercury levels. The temperature is usually around 11 degree Celsius.
The best time to visit Graz is during the spring season months of March to May. The weather is slightly cool, but not too much and pretty comfortable for sightseeing. The rainy season summer months should be generally avoided but if you are looking for lower tariffs then are good for planning a visit.