NWS Jacksonville » Climate Page » St. Simons Island Normals for September
| SSI | August Normals | September Normals | October Normals |
| August Records | September Records | October Records |
| St. Simons Island Normals for September | |||||||
| Day | High | Low | Avg | Pcpn | Year To Date | HDD | CDD |
| 01 | 87 | 74 | 81 | 0.22 | 30.33 | 00 | 16 |
| 02 | 87 | 74 | 80 | 0.22 | 30.55 | 00 | 15 |
| 03 | 87 | 74 | 80 | 0.22 | 30.77 | 00 | 15 |
| 04 | 87 | 74 | 80 | 0.21 | 30.98 | 00 | 15 |
| 05 | 87 | 74 | 80 | 0.22 | 31.20 | 00 | 15 |
| 06 | 86 | 74 | 80 | 0.21 | 31.41 | 00 | 15 |
| 07 | 86 | 73 | 80 | 0.21 | 31.62 | 00 | 15 |
| 08 | 86 | 73 | 80 | 0.21 | 31.83 | 00 | 15 |
| 09 | 86 | 73 | 80 | 0.21 | 32.04 | 00 | 15 |
| 10 | 86 | 73 | 79 | 0.20 | 32.24 | 00 | 14 |
| 11 | 86 | 73 | 79 | 0.19 | 32.43 | 00 | 14 |
| 12 | 86 | 73 | 79 | 0.19 | 32.62 | 00 | 14 |
| 13 | 85 | 72 | 79 | 0.19 | 32.81 | 00 | 14 |
| 14 | 85 | 72 | 79 | 0.19 | 33.00 | 00 | 14 |
| 15 | 85 | 72 | 79 | 0.18 | 33.18 | 00 | 14 |
| 16 | 85 | 72 | 78 | 0.18 | 33.36 | 00 | 13 |
| 17 | 85 | 72 | 78 | 0.18 | 33.54 | 00 | 13 |
| 18 | 84 | 71 | 78 | 0.18 | 33.72 | 00 | 13 |
| 19 | 84 | 71 | 78 | 0.18 | 33.90 | 00 | 13 |
| 20 | 84 | 71 | 78 | 0.18 | 34.08 | 00 | 12 |
| 21 | 84 | 71 | 77 | 0.17 | 34.25 | 00 | 12 |
| 22 | 84 | 70 | 77 | 0.18 | 34.43 | 00 | 12 |
| 23 | 83 | 70 | 77 | 0.18 | 34.61 | 00 | 12 |
| 24 | 83 | 70 | 77 | 0.18 | 34.79 | 00 | 12 |
| 25 | 83 | 70 | 76 | 0.18 | 34.97 | 00 | 11 |
| 26 | 83 | 69 | 76 | 0.18 | 35.15 | 00 | 11 |
| 27 | 83 | 69 | 76 | 0.18 | 35.33 | 00 | 11 |
| 28 | 82 | 69 | 75 | 0.18 | 35.51 | 00 | 11 |
| 29 | 82 | 68 | 75 | 0.18 | 35.69 | 00 | 10 |
| 30 | 82 | 68 | 75 | 0.18 | 35.87 | 00 | 10 |
| Month | 84.7 | 71.6 | 78.1 | 5.76 | 35.87 | 0000 | 0395 |
| Season | - | - | - | - | - | 0000 | 0395 |