The official National Weather Service forecast for Mattawamkeag — 45.5137°N, 68.3545°W, 9.7 miles from I-95. Forecasts here are written by NWS CAR, this county’s forecast office.
| Penobscot County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 26 | 30 | 39 | 52 | 65 | 73 | 79 | 78 | 70 | 57 | 43 | 32 | 54 |
| Avg low °F | 8 | 9 | 18 | 30 | 41 | 50 | 57 | 55 | 47 | 37 | 27 | 16 | 33 |
| Precip in | 3.1 | 2.7 | 3.4 | 3.6 | 3.6 | 4.2 | 3.8 | 3.6 | 3.8 | 4.8 | 3.9 | 4.4 | 44.9 |
1996–2025 normals for Penobscot County — the climate division Mattawamkeag sits in. All-time county record high 99.1°F (1975-08-03); record low -34.5°F (1962-02-02). Source: NOAA / National Weather Service.