The Fleurieu Peninsula has a temperate climate. While it shares the same hot, dry summers (November to March) and cool winters (June to September) as the mainland, the sea breeze tends to take the edge off the extremely hot summer days. The average temperatures given below are for Adelaide.
| Month | Temp (°C) | Rainfall (mm) | Humidity (%) | Sunshine (hours) |
| Jan | 60 - 82 | 0.7 | ||
| Feb | 60 - 82 | 0.7 | ||
| Mar | 58 - 78 | 0.8 | ||
| Apr | 53 - 72 | 1.5 | ||
| May | 49 - 65 | 2.3 | ||
| Jun | 45 - 61 | 2.1 | ||
| Jul | 44 - 59 | 2.5 | ||
| Aug | 46 - 60 | 2 | ||
| Sep | 48 - 64 | 1.7 | ||
| Oct | 51 - 70 | 1.4 | ||
| Nov | 54 - 75 | 1 | ||
| Dec | 58 - 78 | 0.9 |