Colorado
2+ weeks after the spring frost reference
The source anchor is the average last spring frost. This is an earliest reference, not an open-ended planting season.
- Check garden soil temperature, workable soil and current weather.
- Protect or delay frost-sensitive plants while frost remains possible.
A NOAA station’s median 32°F freeze date is a different measure. Substituting it is an application calculation, not a published local calendar.