How to find your last frost date

Your calendar starts from two dates: the average last spring frost and the average first autumn frost. Here is where to find them, country by country.

Last updated 1 November 2026 · Sources checked on 1 November 2026

The quickest way: type your town into SowClock. We compute frost dates from weather-station records for towns in 17 countries (see our method). For other places, or to double-check, use these official sources.

United States

What the sources say

NOAA's U.S. Climate Normals (1991-2020) give, for thousands of stations, the dates after which the chance of a 32 °F (0 °C) freeze drops below 50 %, 40 %, 30 %, 20 % and 10 %. The usual "average last frost date" is the 50 % date.

(source: NOAA Climate.gov; NOAA NCEI, U.S. Climate Normals)

NOAA Climate.gov explains how to find them: on NCEI's Annual/Seasonal Normals page, choose the data type "10% probability date of last 32F occurrence or later" (and the other probabilities), then preview the results for your station. Your county's university extension office can also help.

Canada

What the sources say

Environment and Climate Change Canada publishes the Canadian Climate Normals for stations across the country (1991-2020 and earlier periods). Search by location name, province or distance from a city.

(source: Environment and Climate Change Canada)

United Kingdom

What the sources say

The Met Office notes a clear north-south pattern: in southern and coastal areas the average last air frost tends to come before the end of April; further north and on higher ground it often extends well into May, and in a few places into June.

(source: Met Office)

Planting out tender plants in the UK

For tender plants the RHS gives typical first safe planting-out times: first to second half of May on the south-west tip and the south coast of England; second half of May in southern England and south Wales; end of May in the Midlands, north-west England, Yorkshire and north Wales; early June in north-east England, southern Scotland and Northern Ireland; mid June in the Highlands and northern Scotland.

(source: RHS)

Ireland

What the sources say

Met Éireann notes that air frost is not infrequent at inland locations, even in May.

(source: Met Eireann)

Australia

What the sources say

The Bureau of Meteorology publishes frost potential maps (average number of nights per month and year below temperature thresholds) and regional climate guides for agriculture, some of which give the average date of the last frost at local stations. It stresses that frost is very localised, with frost hollows in valleys.

(source: Bureau of Meteorology, frost maps; Bureau of Meteorology, climate guides; Bureau of Meteorology)

New Zealand

What the sources say

Earth Sciences New Zealand (formerly NIWA) publishes the mean number of days of ground frost.

(source: Earth Sciences New Zealand)

SowClock does not cover New Zealand yet: the open station records we use do not have enough complete years there (see coverage).

Everywhere else

Our explanation

Look for your national weather service's climate normals or climate averages, ideally for a station near you at a similar height. Experienced local gardeners, allotment societies and garden centres usually know the local frost dates too. Then type them into SowClock.

Good to know: the limits

Frost dates can vary over short distances because of elevation and topography; averages describe past weather and do not predict a given year. (source: Utah State University Extension) Gardens in valleys, in open countryside or on high ground often get later spring frosts than the nearest town station. (source: Met Office)

Frequently asked questions

Is the hardiness zone the same as a frost date?

No. The RHS points out that USDA hardiness zones classify places only by their average minimum winter temperature. They tell you which perennials survive the winter, not when the last spring frost usually happens.

Which frost date should I use if sources disagree?

Use the station closest to your garden and most like it (height, distance from the sea, town or countryside). When in doubt, take the later spring date and the earlier autumn date: it costs a week or two, and protects tender plants.

A friendly guide, not a guarantee. Frost dates are averages of past weather, not forecasts: a frost can come later than the average in any year. Crop timings are general rules from university extension services; your soil, microclimate, variety and the weather on the day matter too. Check your local forecast before planting out tender plants.

Sources

Sources checked on 1 November 2026.