The official National Weather Service forecast for Lyons — 40.2247°N, 105.2714°W, 17.6 miles from I-25. Forecasts here are written by NWS BOU, this county’s forecast office.
| Boulder County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 39 | 40 | 48 | 55 | 63 | 75 | 81 | 79 | 72 | 59 | 48 | 40 | 58 |
| Avg low °F | 17 | 17 | 23 | 29 | 37 | 46 | 52 | 50 | 43 | 33 | 24 | 17 | 32 |
| Precip in | 1.0 | 1.2 | 1.9 | 2.7 | 2.9 | 1.7 | 2.1 | 1.9 | 1.6 | 1.4 | 1.0 | 1.0 | 20.4 |
1996–2025 normals for Boulder County — the climate division Lyons sits in. All-time county record high 94.0°F (2005-07-22); record low -32.1°F (1951-02-01). Source: NOAA / National Weather Service.