Frost Dates 2026: First & Last Frost by ZIP or City

What do frost dates actually mean?

Frost dates are the two dates that bracket your growing season: the last frost date in spring and the first frost date in autumn. Enter a US ZIP code or any city worldwide — this frost dates by zip code and city tool is also a growing zone finder, and it reads 15 years of your own local temperature records rather than a national average. Turn the answer into sowing dates with the planting calendar.

Your last spring frost date is the day after which a freezing night becomes unlikely, and your first fall (autumn) frost date is the day a freezing night becomes likely again. The stretch between the two is your growing season — the number of days you have to grow frost-tender crops like tomatoes, peppers, beans and cucurbits outdoors. Frost is conventionally defined as an air temperature at or below 0 °C / 32 °F, though tender tropical plants can be damaged a few degrees above that.

The crucial word is likely. Frost dates are probabilities, not promises — which is exactly why this tool shows you a full probability table rather than a single date. A “50% date” means half of recent years still had frost after that day; the “safe” date is the one only one year in ten crosses. Serious growers plant hardy crops against the 50% date and tender crops against the safe date, and keep fleece handy either way.

Meteorologists also grade freezes by severity, because plants respond very differently to each:

• Light freeze, 0 °C / 32 °F: kills tender plants (basil, tomato, squash); hardy vegetables are untouched.
• Moderate freeze, −2 °C / 28 °F: widely destructive to most unprotected vegetation; semi-hardy crops are damaged.
• Hard freeze, −4 °C / 24 °F: heavy damage to almost everything still growing; ends the season for all but the toughest crops (kale, leeks, parsnips).

Why a 15-year percentile method beats station normals

Almost every frost-date lookup on the internet works the same way: it matches your ZIP or postcode to the nearest official weather station and reads that station’s published 30-year climate normals. That approach has two quiet problems. First, the nearest station can be 30–50 km away, at a different elevation, nearer the coast, or inside a city heat island — any of which can shift frost dates by two weeks or more. Second, published normals are frozen snapshots of a past period, while recent decades have warmed measurably.

This tool instead pulls roughly 15 years of daily minimum temperatures for your exact coordinates (reanalysis data interpolated to your latitude/longitude, not a distant station) and computes the statistics live:

Because everything is computed from your own coordinates, the tool works identically for a Kansas farm, a Scottish glen, a Himalayan hill station or a frost-free Mumbai balcony — no ZIP-code lock, no country limit.

Typical frost dates in 32 cities around the world

The table below gives typical (median) frost dates for well-known cities, as a quick orientation. Type any of them — or your own town — into the finder above for the full probability table computed live.

Southern-hemisphere rows read in their own seasons: “last frost early September” in Melbourne is their spring. Tropical lowland cities — Mumbai, Singapore, Nairobi, Lagos, most of coastal Brazil — are frost-free and plan by rainfall and heat instead.

What should I plant before the last frost?

How do I protect plants from a frost?

When a frost night is forecast after you have planted, most damage is avoidable with a few hours of preparation:

1. Cover before dusk. Horticultural fleece, old bedsheets, cardboard boxes or upturned buckets trap the day’s soil heat. Covers should reach the ground; remove them mid-morning.
2. Water the soil in the afternoon. Moist soil stores and releases more heat overnight than dry soil — a counter-intuitive but well-documented effect.
3. Move containers. Pots freeze from all sides; shift them against a house wall or indoors for the night.
4. Know your cold spots. Cold air drains downhill and pools in hollows and behind solid fences — frost pockets can run several degrees colder than a slope 20 m away.
5. After a surprise frost, don’t prune blackened growth immediately; wait until new growth shows what actually died, and water lightly once thawed. Many plants that look destroyed at dawn recover if thawed slowly in shade.

For timing everything against these dates, the Planting Calendar converts your frost date into per-crop sowing windows, and the Seed-starting Calculator counts back the indoor-sowing weeks for you.

Sources: Wikipedia — Frost · Wikipedia — Growing season · US National Weather Service — Frost/Freeze safety · University of Minnesota Extension — Protecting plants from frost

Can I look up frost dates by ZIP code?

Yes. Type any 5-digit US ZIP code — for example 90210 or 10001 — straight into the search box above and the finder resolves it to that ZIP’s own coordinates, then computes the full probability table from 15 years of daily temperatures at that exact spot. Everywhere else in the world, just type your city or town name: the same engine works for London, Delhi, Sydney, Nairobi or a Himalayan hill station. Either way you get identical output — last spring frost, first fall frost, the 90% / 50% / 10% table, monthly risk and growing-season length. Turn the result into per-crop sowing dates with the planting calendar.

Using the frost dates finder in 30 seconds

1. Type a ZIP code or city. Frost dates are then read from 15 years of local records.
2. Read both dates. Last spring frost and first autumn frost bracket your season.
3. Use the probability table. The 10% column is the safe date for tender crops.

Turn those dates into sowing plans with the planting calendar and the seed starting calculator. Choose plants that suit the season length using the plant finder, and protect tender crops early rather than late.