The official National Weather Service forecast for Sebastian — 27.8164°N, 80.4706°W, 5.2 miles from I-95. Forecasts here are written by NWS MLB, this county’s forecast office.
| Indian River County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 72 | 76 | 79 | 83 | 87 | 89 | 91 | 91 | 89 | 85 | 79 | 75 | 83 |
| Avg low °F | 51 | 54 | 58 | 62 | 67 | 72 | 73 | 74 | 73 | 68 | 61 | 55 | 64 |
| Precip in | 2.1 | 2.0 | 2.5 | 2.9 | 4.0 | 7.2 | 6.0 | 7.0 | 7.3 | 4.5 | 2.5 | 2.5 | 50.5 |
1996–2025 normals for Indian River County — the climate division Sebastian sits in. All-time county record high 98.6°F (1985-06-04); record low 23.0°F (1977-01-20). Source: NOAA / National Weather Service.