In January the average temperature is 9°C and in July it is 31°C. Forecasts and weather for specific days can be found at this link: http://uk.weather.com/weather/today-San-Gimignano-ITXX0333 or at http://www.lamma.rete.toscana.it/prev. July and August (summer) are the best months for visiting San Gimignano as rainy days are rare, with rainfall below four inches. Although the temperature is the highest of the year, it is still not very high. The temperature is around 29.5ºC and the average low temperature is around 22.7ºC. September reaches a rainfall level of 11 inches, the highest of the year. The next few months rainfall remains a bit over 10 inches until December. January and February are dry. Spring is a little bit rainier than summer. Winter temperatures reach about 10ºC on average and the lowest temperature is 4.5ºC approximately. Because winter is very cold, it is also a good time to visit San Gimignano .
Around the Region
When you travel to San Gimignano, you should experience the surrounding Tuscan landscape. Spring (Apr-Jun) and autumn (Sep-Oct) are the best seasons to travel to Tuscany due to the fine Tuscan weather, endless open air activities to engage in, and less crowded streets. Prices are lower than in the summer. July and August (summer) are hot and rainy months and very busy periods becuase many Italians and foreigners head to Tuscany on holiday. July temperature can be from 23ºC to 30ºC c and the valleys are hotter with temperatures of up to 40ºC. The rain arriving in mid-August lowers temperatures. September and October still have warm days that are ideal for travel through Tuscany. The towns are not crowded and days are fine and dryer. November has lower temperatures and many visitors join the olive harvest, a typical annual activity. Winters in Tuscany reach temperatures of 3.5ºC to 5.5ºC. These are the lowest temperatures in the cold wet winters in Tuscany.