February in Siena is the rainiest month of the year. In February, the weather in Siena is typically cold. Average daily high temperature in February is about 8 degrees above zero. On average, Siena has 15 rainy, 9 sunny, 4 partly cloudy, and 1 cloudy day in February. The rains are usually heavy. February as well as January, March, November, and December is considered the most uncomfortable time to visit Siena.