The official National Weather Service forecast for Westfield — 42.1251°N, 72.7495°W, 2.3 miles from I-90.
| Hampden County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 34 | 38 | 46 | 59 | 70 | 78 | 83 | 81 | 74 | 62 | 50 | 39 | 60 |
| Avg low °F | 16 | 19 | 26 | 35 | 46 | 55 | 60 | 59 | 52 | 41 | 31 | 22 | 38 |
| Precip in | 3.6 | 3.1 | 3.9 | 4.2 | 4.1 | 4.5 | 4.5 | 4.2 | 4.6 | 4.8 | 3.4 | 4.5 | 49.4 |
1996–2025 normals for Hampden County — the climate division Westfield sits in. All-time county record high 98.3°F (2011-07-23); record low -21.3°F (1961-01-22). Source: NOAA / National Weather Service.