The official National Weather Service forecast for Hayfork — 40.5543°N, 123.1831°W, 43.1 miles from I-5. Forecasts here are written by NWS EKA, this county’s forecast office.
| Trinity County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 47 | 50 | 55 | 61 | 70 | 80 | 89 | 88 | 81 | 68 | 53 | 45 | 66 |
| Avg low °F | 32 | 31 | 33 | 36 | 41 | 48 | 55 | 54 | 49 | 42 | 36 | 32 | 41 |
| Precip in | 9.8 | 9.1 | 7.6 | 4.2 | 2.2 | 0.7 | 0.1 | 0.2 | 0.8 | 3.2 | 7.0 | 11.7 | 56.6 |
1996–2025 normals for Trinity County — the climate division Hayfork sits in. All-time county record high 107.2°F (2024-07-07); record low 1.1°F (1972-12-09). Source: NOAA / National Weather Service.