Silverthorne, CO 80497 Frost Dates
Silverthorne, CO: when does the frost end?
The NOAA station nearest to 80497 does not report a usable frost-date normal for either event, so no last-frost or first-frost figure is shown here. The USDA hardiness zone below is still real: Zone 4b (-25 to -20°F average annual minimum).
Silverthorne against the rest of the dataset
Silverthorne's growing season runs about 41 days, ranking 40,244 of 40,283 US ZIP codes measured here, longest to shortest. Within CO, it ranks 608 of 624.
Learn more
Before leaning on 80497's figures: the methodology explains exactly which NOAA and USDA figures feed 80497's numbers, while zone vs. frost date explains why Zone 4b and Silverthorne's frost date answer different questions.