GreenlyBelfast: frost dates
United Kingdom
In Belfast the last spring frost usually comes around 18 April and the first autumn frost around 19 November, which leaves about 215 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground around 15 June.
| Last spring frost | around 18 April |
|---|---|
| First autumn frost | around 19 November |
| Frost-free days | 215 days |
Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.
When to sow and plant
| Crop | Sow for seedlings | Plant out in a greenhouse | Open ground |
|---|---|---|---|
| Bell Pepper | 3 April | 16 June | 7 July |
| Chili Pepper | 20 April | 3 July | 24 July |
| Corn | — | 23 April | sow 14 May |
| Cucumber | 5 May | 16 June | 7 July |
| Eggplant | 7 April | 16 June | 7 July |
| Green Beans | 17 March | 23 April | 14 May |
| Melon | 25 April | 16 June | 7 July |
| Peas | — | 7 March | sow 28 March |
| Physalis | 10 April | 25 May | 15 June |
| Pumpkin | 18 April | 25 May | 15 June |
| Sweet Corn | — | 23 April | sow 14 May |
| Tomato | 29 March | 25 May | 15 June |
| Watermelon | 15 May | 16 June | 7 July |
| Zucchini | 23 April | 25 May | 15 June |
Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day.
Belfast: weather for the next 7 days
Forecast by Open-Meteo. Nights at or below 0 °C are marked as frost.
Planted in autumn
| Crop | Plant around |
|---|---|
| Crocus | 20 October |
| Daffodil | 20 October |
| Garlic | 20 October |
| Hyacinth | 20 October |
| Lily | 20 October |
| Tulip | 20 October |
A month before the first autumn frost, so the roots grow before winter.