# Frost dates for Castle Rock, CO (80104)

**Do this (Safe, 2026-11-02):** Frost season started Sep 17. Keep covers ready for cold nights.

| Risk | Last spring frost | First fall frost | Frost-free days |
|---|---|---|---|
| Safe (1 in 10 years later) | May 24 | Sep 17 | 116 |
| Median | May 9 | Oct 2 | 146 |
| Bold (9 in 10 years later) | Apr 30 | Oct 16 | 169 |

Frost = 32°F. Station: Castle Rock, CO, 4 mi away.

## Next nights (NWS overnight low)

- 2026-11-02: 38°F — Wait (tonight)
- 2026-11-03: 34°F — Cover
- 2026-11-04: 35°F — Cover
- 2026-11-05: 33°F — Cover
- 2026-11-06: 34°F — Cover
- 2026-11-07: 32°F — Cover
- 2026-11-08: 35°F — Cover

Go above 40°F · Wait 37–40°F · Cover 36°F or less · Freeze 28°F or less.

Source: Frost dates: NOAA NCEI U.S. Climate Normals 1991–2020, station Castle Rock, CO (4 mi, 341 ft lower than you). Not endorsed by NOAA. Nights: National Weather Service.

Page: https://frostdatecalculator.com/p/co/castle-rock · JSON: https://frostdatecalculator.com/p/co/castle-rock?format=json