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Last and first frost dates in San Sebastián

Spain

In San Sebastián the last spring frost usually comes around 22 January and the first autumn frost around 3 December, which leaves about 315 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 1 May to 13 August.

Last spring frostaround 22 January
First autumn frostaround 3 December
Frost-free days315 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 is the last frost in San Sebastián?

The last frost in San Sebastián usually comes around 22 January: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 1 January, while corn waits until 6 March. The first autumn frost follows around 3 December, about 315 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha29 November – 25 August8 January – 4 October29 January – 4 October
Ageratumfrom 13 February—from 1 May
Arugula——sow 1 January – 29 October
Basil10 April – 1 October18 May – 8 November8 June – 8 November
Beet——sow 1 January – 4 October
Bell Pepper19 March – 14 June18 May – 13 August8 June – 13 August
Black-eyed Susanfrom 7 November—from 29 January
Bok Choy4 December – 12 October8 January – 16 November29 January – 16 November
Borage——sow 29 January – 9 October
Broad bean——sow 1 January – 25 August
Broccoli——sow 1 January – 18 August
Brussels Sprouts27 October – 16 July11 December – 30 August1 January – 30 August
Busy Lizziefrom 6 November—from 29 January
Cabbage——sow 1 January – 26 July
Calendula——sow from 1 January
Carrot——sow 1 January – 10 September
Cauliflower30 October – 18 August11 December – 29 September1 January – 29 September
Celeriac23 October – 15 June8 January – 31 August29 January – 31 August
Celery23 October – 25 June8 January – 10 September29 January – 10 September
Celosiafrom 4 Marchfrom 18 Aprilfrom 9 May
Chamomile——sow 1 January – 29 September
Chayote17 November – 8 June13 February – 4 September6 March – 4 September
Chickpea——sow 1 January – 15 August
Chicory16 November – 9 September—1 January – 4 October
Chili Pepper19 March – 21 July18 May – 19 September8 June – 19 September
China asterfrom 27 Marchfrom 18 Mayfrom 8 June
Chives——sow 1 January – 20 September
Cilantro——sow 1 January – 30 September
Corn——sow 6 March – 15 August
Corn poppy——sow from 1 January
Cosmosfrom 4 Marchfrom 18 Aprilfrom 9 May
Cucumber20 April – 21 August18 May – 18 September8 June – 18 September
Daikon——sow 1 January – 27 September
Delphiniumfrom 13 October—from 1 January
Dill——sow 1 January – 10 October
Edging lobeliafrom 6 November—from 29 January
Eggplant19 March – 14 June18 May – 13 August8 June – 13 August
Florence fennel24 November – 25 August8 January – 9 October29 January – 9 October
Foxglovefrom 25 September—from 1 January
Garden sorrel——sow 1 January – 28 September
Green Beans——sow 9 May – 23 August
Hollyhock——sow from 1 January
Hyssop——sow 1 January – 21 August
Kale——sow 1 January – 22 September
Kiwano9 March – 28 August10 April – 29 September1 May – 29 September
Kohlrabi——sow 1 January – 2 October
Leek2 October – 6 June11 December – 15 August1 January – 15 August
Lemon balm——sow 1 January – 24 September
Lettuce——sow 1 January – 7 October
Lisianthusfrom 15 Septemberfrom 11 Decemberfrom 1 January
Lovage——sow from 1 January
Luffa6 April – 22 June18 May – 3 August8 June – 3 August
Marigoldfrom 27 Novemberfrom 8 Januaryfrom 29 January
Marjoram19 March – 9 September—8 June – 8 November
Melon20 April – 8 August18 May – 5 September8 June – 5 September
Microgreens——sow 9 May – 19 November
Moringa9 April – 14 September3 June – 8 November24 June – 8 November
Moss rosefrom 13 November—from 29 January
Mustard greens——sow 1 January – 19 October
Napa cabbage6 December – 19 September8 January – 22 October29 January – 22 October
Nasturtiumfrom 1 Decemberfrom 8 Januaryfrom 29 January
Okra6 April – 2 September18 May – 14 October8 June – 14 October
Oregano12 October – 30 August11 December – 29 October1 January – 29 October
Pansyfrom 16 Octoberfrom 11 Decemberfrom 1 January
Parsley——sow 1 January – 18 September
Parsnip——sow 1 January – 7 August
Peanut11 April – 29 July18 May – 4 September8 June – 4 September
Peas——sow 1 January – 20 September
Petuniafrom 16 Marchfrom 18 Mayfrom 8 June
Physalis24 February – 26 July10 April – 9 September1 May – 9 September
Pumpkin6 April – 27 June18 May – 8 August8 June – 8 August
Purple coneflowerfrom 10 October—from 1 January
Radish——sow 1 January – 3 November
Sage23 October – 26 August11 December – 14 October1 January – 14 October
Scarlet sagefrom 17 February—from 1 May
Snapdragonfrom 7 Octoberfrom 11 Decemberfrom 1 January
Soybean——sow 8 June – 14 September
Spinach——sow 1 January – 9 October
Stevia20 February – 17 July10 April – 4 September1 May – 4 September
Stock——sow from 1 January
Sunflower——sow from 9 May
Sweet alyssum——sow from 1 January
Sweet Corn20 February – 9 September14 March – 1 October4 April – 1 October
Sweet peafrom 30 Octoberfrom 11 Decemberfrom 1 January
Sweet William——sow from 1 January
Swiss Chard——sow 1 January – 4 October
Thyme——sow 1 January – 15 August
Tomato17 February – 22 June10 April – 13 August1 May – 13 August
Turnip——sow 1 January – 6 October
Watercress——sow 1 January – 17 October
Watermelon20 April – 27 July18 May – 24 August8 June – 24 August
Zinniafrom 29 Aprilfrom 3 Junefrom 24 June
Zucchini27 April – 26 August18 May – 16 September8 June – 16 September

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. 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.

When the soil warms up in San Sebastián

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 9 days before the last spring frost and 15 °C 99 days after it.

SoilDateAgainst the last spring frost
5 °Calready in the first week of January—
10 °C13 January9 days earlier
15 °C1 May99 days later
18 °C8 June137 days later

Frost dates near San Sebastián

Of the nearest cities on our list, the last spring frost ends earliest in Bayonne (26 January) and latest in Vitoria-Gasteiz (6 April).

CityDistanceLast spring frostFirst autumn frost
Bayonne45 km26 January17 December
Pamplona63 km21 March30 November
Vitoria-Gasteiz77 km6 April24 November
Bilbao77 km14 March26 December
Logroño102 km12 March4 December

Seeds, seedlings and markets in San Sebastián

Within 15 km of San Sebastián OpenStreetMap lists 4 garden centres, 3 farm-supply shops, 6 markets and 4 farm shops (collected 27 October 2026). The nearest garden centre to the city centre is Loraldi, 6 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in San Sebastián

Frosts in San Sebastián usually come from about 3 December to about 22 January. These plants have indoor care in their Greenly cards and are harvested quickly, so they can be sown on a windowsill in winter.

Weather in San Sebastián by month

Average weather in San Sebastián over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: June–September (21.3–23.6 °C). No month averages below 0 °C at night; the coldest nights, in January, average 5 °C. About 1726 mm of rain falls in a year, on 177 days; November is the wettest month (230 mm) and July the driest (73 mm).

MonthDay, °CNight, °CRain, mmRainy days
January11.1520516
February13.25.915014
March14.26.815617
April15.98.312215
May18.210.712717
June21.314.210914
July22.7167313
August23.616.39912
September22.114.312713
October19.712.413913
November14.78.623018
December12.86.918915

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

CropWhen to plant
Bearded Irisby 3 November
Crocusby 3 November
Daffodilby 3 November
Garlic1 October – end of December
Grape hyacinthby 3 November
Helleboreby 3 November
Hyacinthby 3 November
Lilyby 3 November
Ornamental onionby 3 November
Peonyby 3 November
Saffronby 3 November
Snowdropby 3 November
Tulipby 3 November
Wild garlicby 3 November

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).