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Frost Date Lookup

Type your city or state to find your average last spring frost date, first fall frost date, growing season length, and USDA hardiness zone.

Your last spring frost date and first fall frost date are the two most important numbers in vegetable gardening. Every seed packet, every planting guide, and every sowing calendar is built around them.

Get them wrong and you risk losing tender seedlings to a late freeze — or watching your tomatoes get killed by an early autumn frost before they've fully ripened.

The dates shown here are calculated from 30-year NOAA climate normals (1991–2020) — the same dataset used by the USDA, Cooperative Extension Services, and most professional growers across the US and Canada. The 50% date is the statistical average: half the years in the dataset recorded their last frost before that date, half after.

Because frost is never perfectly predictable, we also show the 10% safest date (almost certainly frost-free) and the 90% earliest date (for gardeners willing to take a calculated risk with row cover protection).

Below the lookup tool you'll find a full frost tolerance planting guide showing which vegetables are hardy enough to plant before last frost and which must wait, a USDA hardiness zone reference table, and answers to the most common questions about using frost dates in your garden planning.

Find Your Frost Dates

Search by city name or US state abbreviation. Results include last spring frost, first fall frost, growing season length, and probability ranges.

Covers 130+ US and Canadian cities · Based on 30-year NOAA climate normals (1991–2020) · Free, no sign-up needed.

Start typing to find frost dates for your city.

What Are Frost Dates?

Frost dates are the average calendar dates of the last spring frost and the first fall frost for a given location. They are calculated from decades of weather station data and represent the statistical midpoint — meaning there is roughly a 50% chance of frost before or after that date in any given year.

These two dates define your growing season — the frost-free window in which tender crops like tomatoes, peppers, cucumbers, and squash can grow outdoors without protection. Cold-hardy crops like kale, peas, and broccoli can push outside this window, but warm-season vegetables cannot survive a hard freeze.

The dates in this tool are based on 30-year NOAA climate normals (1991–2020) sourced from official weather stations across the US and Canada — the same dataset used by the USDA, Cooperative Extension Services, and most professional growers.

What Is a Last Spring Frost Date?

Your last spring frost date is the average final date each year when air temperatures at ground level drop to or below 32°F (0°C). After this date, the probability of frost decreases significantly — but frost can still occur, especially in low-lying areas, on clear calm nights, and at higher elevations.

The 50% average date shown in this tool means there is still a 1-in-2 chance of frost after that date in any given year. For cold-sensitive crops like tomatoes, basil, and peppers, most gardeners wait until the 10% safest date (about 2–3 weeks later) before transplanting outdoors — especially without row cover protection.

Important note on probability

A frost date is not a guarantee — it is a statistical average. Climate variability, local microclimates, urban heat effects, and year-to-year weather patterns all mean actual frost dates can vary by 2–4 weeks from the historical average. Always monitor your local 10-day forecast around your frost date window.

Why Spring Frost Dates Matter

Knowing your last frost date is the foundation of seasonal vegetable planning. It tells you:

  • 📅

    When to start seeds indoors

    Count backwards from your last frost date. Tomatoes need 6–8 weeks indoors, peppers 10–12 weeks, courgettes 3–4 weeks. Get this wrong and you transplant too early (frost damage) or too late (lost growing season).

  • 🌱

    When it's safe to transplant outdoors

    Tender seedlings started indoors must wait until after your last frost date — and should be hardened off for 7–10 days first by gradually increasing outdoor exposure.

  • 🌡️

    Which crops need season extension tools

    In Zone 5 or colder, a last frost date of May 1 or later makes it difficult to grow long-season crops like peppers and melons without cold frames, row covers, or a greenhouse head start.

  • 📆

    How to time succession sowings

    Fast-maturing crops like lettuce, radishes, and spinach can be sown in several batches starting weeks before last frost right through the season for a continuous harvest.

  • 🗺️

    Whether a crop variety suits your season

    A tomato variety needing 85 days to maturity planted after a June 1 last frost may not ripen before a September first fall frost. Frost dates let you do the maths before you sow.

What Is a First Fall Frost Date?

Your first fall frost date is the average earliest date each autumn when temperatures drop to 32°F (0°C) or below. For warm-season crops — tomatoes, courgettes, beans, cucumbers — this date signals the end of the productive season. Once frost hits, tender plants collapse overnight.

The first fall frost date is equally important for planning a second season.

Cold-tolerant crops like kale, spinach, carrots, and turnips can be direct-sown 8–10 weeks before first fall frost for a productive autumn harvest. Some crops, like parsnips and Brussels sprouts, are actually improved by exposure to frost, which converts starches to sugars.

Why Fall Frost Dates Matter

Your first fall frost date helps you plan the end of season and a second planting window:

  • 🍅

    Harvest before frost damage

    Long-season crops like winter squash, sweet potato, and dry beans need to be harvested before the first frost kills the plant or damages the fruit. Count back from your first fall frost date when selecting varieties.

  • 🥬

    Time your fall sowings

    Sow fast-maturing cool-season crops (spinach, radish, turnip, lettuce) 6–8 weeks before first fall frost. Slower crops like broccoli, kale, and cabbage need 10–12 weeks — meaning you should be sowing them in mid-summer.

  • 🌿

    Protect tender perennial herbs

    Basil, lemon verbena, and other tender herbs must be brought indoors or harvested before the first frost. Hardy herbs like thyme, rosemary (in Zone 7+), and sage can stay out.

  • ❄️

    Plan season extension into autumn

    A row cover or cold frame can push your effective first frost date 4–6 weeks later, keeping salads, spinach, and chard productive well into winter — even in Zone 5 or 6.

Frost Dates by USDA Hardiness Zone

If your city isn't listed above, use your USDA zone as a guide. Find your zone at the USDA Plant Hardiness Zone Map.

Zone Last Spring Frost First Fall Frost Growing Season Example Regions
Zone 3 Jun 1 Sep 1 ~90 days Northern MN, Interior AK, Prairie Canada
Zone 4 May 15 Sep 15 ~120 days Minneapolis MN, Bismarck ND, Calgary AB
Zone 5 May 1 Oct 1 ~150 days Chicago IL, Denver CO, Burlington VT
Zone 6 Apr 15 Oct 15 ~180 days Washington DC, Kansas City MO, Louisville KY
Zone 7 Apr 1 Nov 1 ~210 days Atlanta GA, Nashville TN, Dallas TX
Zone 8 Mar 1 Nov 20 ~265 days Seattle WA, Houston TX, Charlotte NC
Zone 9 Feb 1 Dec 5 ~300 days Phoenix AZ, Sacramento CA, New Orleans LA
Zone 10 Frost rare Frost rare ~365 days Miami FL, San Diego CA
Zone 11 No frost No frost Year-round Hawaii

What Can You Plant — and When?

Not all vegetables react to frost the same way. Use this guide alongside your frost dates above to know exactly when each crop is safe to sow or transplant outdoors.

🍅

Tender Crops — Plant after last frost

Killed by any frost. Wait until night temps stay above 10°C (50°F).

Tomatoes Peppers Aubergine / Eggplant Cucumbers Courgette / Zucchini Squash Melons Basil Sweet Corn Beans (French) Sweet Potato

Timing: Start seeds indoors 6–10 weeks before your last frost date. Move outside only after the 10% safest date (all frost risk gone). Tomatoes and peppers need soil temperatures above 15°C to thrive.

🥗

Half-Hardy Crops — Plant near last frost date

Tolerate light frost (−1°C to −2°C) but not a hard freeze.

Lettuce Beets Swiss Chard Radishes Fennel Coriander / Cilantro Celery Artichoke Parsley Endive

Timing: Transplant or direct sow 1–2 weeks before your average 50% last frost date. A light frost will cause some damage but usually not kill established plants. Use row cover to protect if a cold snap is forecast.

🥬

Hardy Crops — Plant weeks before last frost

Survive hard frosts down to −5°C (23°F) or colder.

Kale Spinach Peas Broccoli Cabbage Brussels Sprouts Cauliflower Carrots Turnips Leeks Onions (sets) Garlic Parsnips Broad Beans

Timing: Direct sow or transplant 4–6 weeks before your last frost date — or as soon as soil can be worked. In fall, sow 8–10 weeks before first frost for a second harvest. Many improve in flavour after a light frost converts starches to sugars.

How to Use Your Frost Dates

S

Sowing Indoors

Count back from your last spring frost date to find when to start seeds indoors. Tomatoes need 6–8 weeks, peppers 10–12 weeks, and cucumbers just 3–4 weeks before transplanting.

T

Transplanting Outside

Move tender transplants outside after your last frost date. Harden off seedlings for 7–10 days first by placing them outside for a few hours per day, increasing exposure gradually.

H

Planning Your Harvest

Add each crop's days-to-maturity to its transplant or direct-sow date. Aim to harvest at least 4 weeks before your first fall frost for long-season crops like squash and sweet potato.

F

Fall Planting

Use your first fall frost date to plan a second season. Cold-tolerant crops like kale, spinach, and carrots can be sown 8–10 weeks before first frost for a fall harvest.

Frequently Asked Questions

What is a last frost date?

Your last frost date is the average calendar date after which ground-level temperatures are unlikely to drop below 32°F (0°C) in spring. It's a statistical average based on historical weather data — not a guarantee. There's still a 10–30% chance of frost after this date, which is why hardening off your plants matters.

What is a first frost date?

Your first fall frost date is the average date when temperatures first drop to 32°F (0°C) or below in autumn. Use it to plan your end-of-season: bring in tender plants, start fall crops, and begin storing root vegetables before the ground freezes.

How accurate are these dates?

The dates are based on 30-year NOAA climate normals (1991–2020) and represent the 50% probability date — meaning there's an equal chance frost will occur before or after this date. For more certainty, use the 10% probability date (about 2–3 weeks later in spring) for cold-sensitive crops like basil and tomatoes.

What is a USDA hardiness zone?

USDA Plant Hardiness Zones are based on the average minimum winter temperature in a given area. They are divided into 13 zones (1–13), each split into "a" (colder) and "b" (warmer) halves. Zone 5b means average minimum winter lows of −15°F to −10°F (−26°C to −23°C). Zones help you choose perennials, trees and shrubs that will survive your winters — but for annual vegetable planning, frost dates are more directly useful.

How do I extend my growing season?

You can effectively shift your frost dates 4–6 weeks earlier in spring and later in fall using season extension tools: row covers and frost blankets protect plants down to 28°F; cold frames add 4–6 weeks; low tunnels with heavy fabric can add 6–8 weeks; and a heated greenhouse removes frost risk entirely. In Zone 5 with cold frames, you can realistically grow as if you were in Zone 6.

My city isn't listed — what do I do?

Find the nearest large city in the same region, or use the USDA Zone map (planthardiness.ars.usda.gov) to identify your zone and then use the zone reference table above. Local cooperative extension offices also publish frost date data specific to your county — search "[your county] frost dates extension" for highly local data.

Use These Dates in Your Planning

Plug your frost dates straight into these free tools.

EdenVatika App

Know your frost dates.
Now automate your whole season.

Save your location once and EdenVatika auto-generates a planting calendar for every crop in your garden — sow dates, transplant reminders, and harvest windows all calculated from your actual frost dates.

  • 📅

    Auto planting calendar

    Zone-aware schedule for every crop in your garden

  • 🔔

    Frost warning alerts

    Get notified when a late frost is forecast (Pro)

  • 📍

    Location-based planning

    Set your location once — all dates update automatically

  • 🌡️

    Season extension tracking

    Log your cold frames and tunnel dates to extend your season (Pro)

  • 🤖

    AI garden planner

    Get a full personalised plan based on your location and beds (Pro)

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