The official National Weather Service forecast for Fall River Mills — 41.0046°N, 121.4383°W, 45.8 miles from I-5. Forecasts here are written by NWS STO, this county’s forecast office.
| Shasta County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 50 | 53 | 57 | 64 | 73 | 83 | 92 | 90 | 84 | 71 | 56 | 49 | 68 |
| Avg low °F | 32 | 33 | 35 | 39 | 46 | 53 | 59 | 57 | 52 | 44 | 37 | 32 | 43 |
| Precip in | 6.8 | 6.8 | 6.0 | 3.3 | 2.1 | 0.8 | 0.1 | 0.2 | 0.7 | 2.4 | 5.1 | 8.2 | 42.5 |
1996–2025 normals for Shasta County — the climate division Fall River Mills sits in. All-time county record high 108.7°F (2024-07-07); record low -2.1°F (1972-12-09). Source: NOAA / National Weather Service.