Frost dates · Planting calendars · Worldwide
Your garden runs on two dates.
Here is where to find them.
Every sowing decision you make is measured from the last frost of spring and the first of autumn. Name your town and Safe to Plant works both dates out from its own temperature record, then times 307 crops against them — not against a zone map drawn for somewhere else.
1,801 places in 149 countries, each computed individually.
What you get
Two dates, three answers
The last frost is not a day, it is a distribution. We give you the date frost has finished in nine years out of ten, the average year, and the gamble — and let you move between them with one control.
A calendar, not a chart
Your frost dates become real sowing dates. Start tomatoes on this day, plant them out on that one, expect to pick from here. Every window is arithmetic on your own numbers.
Both hemispheres, one method
The growing year is anchored to July south of the equator, so Melbourne and Manchester are computed the same way and read the same way. No northern-hemisphere assumptions baked in.
Start somewhere
Frost dates for well-known places
By crop
When to plant…
Why this exists
Hardiness zones answer the wrong question
A hardiness zone tells you how cold your worst winter night gets. That is useful when you are choosing a shrub and almost useless when you are deciding whether to sow beans this weekend. For that you need to know when frost stops, when it starts again, and how much of a gambler you are.
Those numbers exist — they are sitting inside decades of daily minimum temperatures — but almost nobody publishes them outside the United States, and nobody publishes them for arbitrary towns. So we compute them: last and first frost at three temperature thresholds, at three percentiles each, plus a week-by-week frost risk curve, for every place in the index.
Then we do the part that actually saves a season: convert each crop's frost-relative timing — the numbers on the back of a seed packet — into dates on your calendar.
Frost dates, briefly
What is a last frost date?
The last frost date is the day in spring after which frost is unlikely at your location. It is not a guarantee - it is a statistic drawn from decades of temperature records, which is why this site shows it as a range of risk levels rather than a single day.
How are these frost dates calculated?
For each location we take 30 years of daily minimum temperature from NASA POWER, find the last spring day and first autumn day at or below freezing in every individual year, and then take percentiles across those years.
Does this work in the southern hemisphere?
Yes. The growing year is anchored to 1 July south of the equator, so spring frost dates fall in September and October and the first autumn frost lands in April or May, as they should.