Sanibel & Captiva Islands Weather Averages (Source: Sanibel/Captiva Chamber of Commerce)
| Average Highs | Average Lows | Monthly Averages | Average Rainfall | Gulf Temperature | ||||
| Month | F | C | F | C | F | C | Inches | Degrees (F) |
| January | 72 | 22 | 55.5 | 13.1 | 63.8 | 17.3 | 2.1 | 66 |
| February | 73.2 | 22.8 | 56.4 | 13.6 | 64.8 | 18.2 | 2.3 | 66 |
| March | 76.5 | 24.7 | 59.8 | 15.4 | 68.2 | 20.1 | 2.3 | 71 |
| April | 81.3 | 26.8 | 64.8 | 18.1 | 73.1 | 22.8 | 1.8 | 77 |
| May | 86.1 | 30.1 | 69.9 | 21.1 | 78 | 25.6 | 4.5 | 82 |
| June | 89.2 | 31.8 | 74 | 22.8 | 81.6 | 27.6 | 9.4 | 86 |
| July | 89.9 | 32.2 | 75.2 | 24 | 82.6 | 28.1 | 8.5 | 87 |
| August | 90.5 | 32.5 | 75.6 | 24.2 | 83.1 | 28.4 | 8.6 | 87 |
| September | 88.9 | 31.6 | 74.5 | 23.6 | 81.7 | 27.6 | 8.2 | 86 |
| October | 83.8 | 28.8 | 68.9 | 20.5 | 76.4 | 24.7 | 3.2 | 81 |
| November | 76.8 | 24.9 | 60.7 | 15.9 | 69.8 | 21 | 1.8 | 73 |
| December | 72.5 | 22.5 | 56.2 | 13.4 | 64.4 | 18 | 1.5 | 68 |
| Average Year | 81 | 27.5 | 65 | 18.8 | 73.9 | 23.2 | 4.5 | 77.5 |