Sofia has a humid continental climate with high temperature amplitudes. The temperatures in Sofia generally remain cooler than other cities of Bulgaria because of the valley in which it is situated. In the hottest month, July, temperatures don't usually exceed 29 °C (84 °F) - 30 °C (86 °F). Through the coldest month - January, temperatures can sometimes fall down to ?17 °C (1.4 °F) ?20 °C (?4 °F). The average annual temperature is 10.5 °C (50.9 °F). Thunderstorms often occur during the summer season. The city receives around 650 millimetres (26 in) annual precipitation with summer maximum and winter minimum. The temperatures in Sofia generally remain cooler than other parts of Bulgaria in summer(not more than 29 °C (84 °F) - 30 °C (86 °F) , due to the high altitude of the valley in which it is situated. Through the coldest month, January, temperatures can sometimes fall down to ?17 °C (1.4 °F) ?20 °C (?4 °F) .