August in Tbilisi is the sunniest and the warmest month of the year. In August, the weather in Tbilisi is typically hot. Average daily high temperature in August is about 27 degrees above zero. On average, Tbilisi has 27 sunny, 2 rainy, and 2 partly cloudy days in August. The rains are usually light. August as well as June and July is considered the most comfortable time to visit Tbilisi.