The official National Weather Service forecast for Bay Saint Louis — 30.3088°N, 89.33°W, 5.2 miles from I-10. Forecasts here are written by NWS LIX, this county’s forecast office.
| Hancock County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 62 | 65 | 72 | 77 | 84 | 89 | 91 | 91 | 87 | 80 | 70 | 64 | 78 |
| Avg low °F | 41 | 45 | 50 | 57 | 65 | 71 | 73 | 73 | 69 | 58 | 48 | 43 | 58 |
| Precip in | 4.8 | 4.6 | 5.0 | 5.4 | 5.0 | 6.7 | 7.0 | 6.8 | 5.3 | 3.5 | 3.7 | 5.2 | 63.0 |
1996–2025 normals for Hancock County — the climate division Bay Saint Louis sits in. All-time county record high 103.8°F (2023-08-27); record low 7.1°F (1985-01-21). Source: NOAA / National Weather Service.