Florence's position in a river basin, walled in by hills to the south and the foothills of the Apennines to the north, largely determines its climate. In summer the city is a like a pressure cooker as heat and humidity soar. July is the worst month (closely followed by August) and there are days when there is not a whisper of air. The average highs hover around 31°C (88°F). Occasionally you can enjoy the temporary relief of a cracking good thunderstorm. Winter, on the other hand, is cool and often wet, although mercifully it doesn't last too long. Average temperatures in January range between 1°C (33°F) and 10°C (50°F) and snow is rare.
| Month | Temp (°C) | Rainfall (mm) | Humidity (%) | Sunshine (hours) |
| Jan | 1 - 10 | 73 | ||
| Feb | 3 - 12 | 69 | ||
| Mar | 5 - 15 | 80 | ||
| Apr | 8 - 19 | 78 | ||
| May | 11 - 23 | 73 | ||
| Jun | 15 - 27 | 55 | ||
| Jul | 17 - 31 | 40 | ||
| Aug | 17 - 31 | 76 | ||
| Sep | 14 - 27 | 78 | ||
| Oct | 10 - 21 | 88 | ||
| Nov | 6 - 15 | 111 | ||
| Dec | 2 - 10 | 91 |