GreenlyFrost dates and when to plant in the Basque Country
Spain
In the Basque Country the last spring frost comes between 22 January (San Sebastián) and 6 April (Vitoria-Gasteiz) — the median of 2016–2025 in 3 cities. The first autumn frost comes between 24 November (Vitoria-Gasteiz) and 26 December (Bilbao). The frost-free season lasts 232–315 days. Tomato: plant out into open ground 1 May – 5 September, earliest in San Sebastián, latest in Bilbao.
Frost dates by city in the Basque Country
| City | Last spring frost | First autumn frost | Frost-free days | Climate zone | Tomato: window |
|---|---|---|---|---|---|
| San Sebastián | 22 January | 3 December | 315 | 270 frost-free days or more | 1 May – 13 August |
| Bilbao | 14 March | 26 December | 287 | 270 frost-free days or more | 12 May – 5 September |
| Vitoria-Gasteiz | 6 April | 24 November | 232 | 210–269 frost-free days | 13 May – 4 August |
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 plant in the Basque Country: windows by crop
The earliest start and the latest end among the cities here, each with its city; every city’s own window is on its page. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.
| Crop | Planting out or sowing |
|---|---|
| Tomato | 1 May (San Sebastián) – 5 September (Bilbao) |
| Cucumber | 2 June (Bilbao) – 11 October (Bilbao) |
| Bell Pepper, Eggplant | 2 June (Bilbao) – 5 September (Bilbao) |
| Zucchini | 2 June (Bilbao) – 9 October (Bilbao) |
| Pumpkin | 2 June (Bilbao) – 31 August (Bilbao) |
| Watermelon | 2 June (Bilbao) – 16 September (Bilbao) |
| Peas | 1 January (San Sebastián) – 13 October (Bilbao) |
| Garlic | Autumn planting: 1 October – end of December |
| Tulip, Daffodil, Crocus, Hyacinth | Autumn planting: by 26 November (Bilbao) |
Weather by month in the Basque Country
Across the 3 cities the warmest month is August (average days 23.6 … 27.6 °C) and the coldest January (average nights 1.3 … 5 °C). No city here averages below 0 °C at night in any month.
| Month | Day, °C | Night, °C | Rain, mm |
|---|---|---|---|
| January | 8.8 … 11.1 °C | 1.3 … 5 °C | 142 |
| February | 11.2 … 13.2 °C | 2.1 … 5.9 °C | 108 |
| March | 12.8 … 14.2 °C | 3.5 … 6.8 °C | 104 |
| April | 15.5 … 16 °C | 5.3 … 8.3 °C | 87 |
| May | 18.2 … 19.1 °C | 8.1 … 10.7 °C | 80 |
| June | 21.3 … 23.8 °C | 12.2 … 14.2 °C | 70 |
| July | 22.7 … 26.6 °C | 14 … 16 °C | 45 |
| August | 23.6 … 27.6 °C | 14.5 … 16.3 °C | 49 |
| September | 22.1 … 23.3 °C | 11.9 … 14.3 °C | 79 |
| October | 19.5 … 19.9 °C | 9.3 … 12.4 °C | 100 |
| November | 12.6 … 14.7 °C | 5.2 … 8.6 °C | 165 |
| December | 10 … 12.8 °C | 3.2 … 6.9 °C | 128 |
Day and night: the lowest … highest monthly average among the cities; rain: the middle city (ERA5 via Open-Meteo).
