USDA Plant Hardiness Zone
Zone 6a Frost Dates & Planting Calendar
4,371 ZIP codes across 31 states fall in zone 6a.
- Zone
- 6a
- Average Annual Low
- -10 to -5°F
- Typical Growing Season
- 164 days
- ZIP Codes
- 4,371
What zone 6a actually tells you
A hardiness zone describes one thing: the average coldest night of the year, which in zone 6a falls between -10 to -5°F. It answers whether a perennial will survive the winter — not when to plant in spring.
Frost dates answer the planting question, and they vary widely inside a single zone. Zone 6a spans 31 states, and a coastal ZIP can differ from an inland one by three weeks despite sharing the zone. Pick your own ZIP code below rather than planting by zone alone.