Frost Dates by ZIP Code

It's the median date of the last spring freeze (32°F) for your area — meaning in half of years the last freeze comes earlier and in half it comes later. It is a coin flip, not a deadline. Planting tender crops exactly on that date carries roughly a 50% chance of meeting a frost, which is why most gardeners wait one to two weeks past it.

No, and this is the single most common misunderstanding in gardening. A USDA hardiness zone is defined by one number only: the average annual extreme minimum winter temperature. It tells you what perennials survive your winter. It says nothing about when frost ends in spring. Atlanta and Dallas–Fort Worth are both zone 8a yet differ by roughly 20 frost-free days; Houston and Seattle are both 9a with completely different growing calendars. The frost dates here are representative medians for each zone, not measurements for your address.

It resolves your 3-digit ZIP prefix to the dominant hardiness zone for that area, which is an approximation. Accuracy is good across flat, uniform regions and worst in the Appalachians, the Rockies and Intermountain West, the Sierra and Cascades, the California coastal ranges, and along coastlines and the Great Lakes, where elevation and water can shift the zone within a few miles. Always sanity-check the zone against the representative cities shown, and override it if it looks wrong. See our methodology.

Zones 10b, 11a and 11b record no 32°F reading in a typical year, so no median last-frost date exists to publish. Rather than invent one, we say so. Zone 10a is genuinely marginal — roughly half of years see no freeze at all — so treat its dates with extra caution.

Almost every planting instruction is written as an offset from your last frost: "start tomatoes indoors 6–8 weeks before last frost", "direct sow beans 1 week after last frost". Once you know your date, the planting calendar converts every one of those offsets into actual dates for your zone.