USDA Hardiness Zone 4
Zone 4 covers an average annual extreme minimum temperature band of -30°F to -20°F.
The two half-zones
Each whole Zone spans 10°F. The a and b halves divide it into 5°F bands.
- 4a
- -30°F to -25°F
- 4b
- -25°F to -20°F
What Zone 4 can answer
- The average annual extreme minimum temperature band used for perennial hardiness context.
- Whether a perennial label lists a matching or colder hardiness range for initial screening.
What it cannot answer
- One exact annual vegetable planting date for every garden in the Zone.
- A last spring freeze, first fall freeze, soil temperature, heat pattern, or current forecast.
Microclimates still matter
Elevation, slope, cold-air drainage, pavement, walls, wind exposure, snow cover, and nearby water can make one garden warmer or colder than a broad map cell. A Zone is a perennial hardiness screen, not a guarantee that every plant will survive.
For annual vegetables, combine the Zone with local freeze normals and current conditions. ZIP lookup results remain on the tool page and do not create indexable ZIP or city pages.
Open the Zone and Frost Date Lookup →