From the Western Isles to Shetland, the islands are maritime through and through: Stornoway's first autumn frost holds off to early November, the latest in Scotland, and hard frost is rare.
The catch is not cold, it is wind and salt. Shelter matters more here than the calendar. There is little high ground in the populated areas, so we give a single maritime figure rather than a lowland/upland split.
Where this covers
- ZE Shetland
- HS the Western Isles
- KA27 Arran
- PA20-PA78 Argyll and its islands, including Bute, Mull and Islay
Frost dates for Shetland, the Western Isles & Argyll
- Maritime (all populated ground): last frost late April, first autumn frost early November, safe to plant out mid May.
Dates are rounded to the nearest half month, from named Met Office stations (1991-2020 averages). One figure covers the whole area: its stations are all low-lying and close to the sea, which sets the frost pattern here.
| Garden | Last spring frost | First autumn frost | Safe to plant out | Season | Station | Confidence |
|---|---|---|---|---|---|---|
| lowland | late April | early November | mid May | ~190 days | Stornoway (15m) | high |
Checked against station records at Lerwick and Tiree.
What this means for growing here
Sow and plant out to these dates rather than a UK calendar, and remember they are regional averages. Your own plot can run two to four weeks later in a frost pocket, or earlier against a warm wall. On exposed island sites, shelter from wind and salt usually does more than chasing an early date. The Planting Calendar turns these into a month-by-month plan.
When to plant out tender crops here
Frost-tender crops go outside only once the safe planting-out date has passed, about two weeks after the last frost: mid May across Shetland, the Western Isles & Argyll. That applies to tomatoes, basil, cucumbers, sweetcorn, peppers, chillies and aubergines grown outdoors. That date is the earliest they can go out, not a promise they will ripen: on exposed ground, shelter from wind and salt matters as much as the date.
Articles for gardens in Shetland, the Western Isles & Argyll
- Growing on Machair: What Actually Works on Scotland's Shell-Sand Ground
- Growing Through the Dark: Shetland and Orkney's Six-Hour Winter Days
- Shelter Belt Planting for Exposed Coastal and Island Gardens
- Crofting Law and Growing Rights
- Seaweed Feed: Kelp Meal, Liquid, and What You Can Actually Gather
Sources
- Met Office: location-specific long-term averages: the 1991-2020 air-frost day counts behind every figure on this page, last verified 2026-07-15
- Derivation method: GrowScotland's own. We treat a month as carrying meaningful frost risk when it averages at least half an air-frost day, take the last such month in spring and the first in autumn, and express each as a half-month band.