When to plant watermelons in Logroño: 28 May – 25 August

In Logroño, watermelon: sow for seedlings from 9 April to 28 July; plant into a greenhouse from 7 May to 25 August; plant out into open ground from 28 May to 25 August.

Watermelon in Logroño: soil, season and weather

In Logroño the soil, not frost, sets the date: the last frost is over around 12 March, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 28 May, 77 days later.

Last spring frost	12 March
Top 7 cm of soil at 18 °C	28 May, 77 days after the last frost
Into an unheated greenhouse	7 May – 25 August; May outside: 9.5 °C at night, 21.6 °C by day; card 18–35 °C
First autumn frost	4 December, 190 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	26 July – 23 October
Days left for picking	131
Daylight	14:01 on 30 April, 14:59 on 28 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, July, has 4 rainy days

The same dates in Logroño hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Logroño: care after planting

Planted on 28 May: in the first weeks water every 5 days.

Feeding, by the card’s schedule from that day:

28 May — feed: balanced (NPK)

Pests and diseases of watermelon to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Logroño during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 30.6 °C. Months that stay below 18 °C even by day on average: November (13.5 °C) and December (10.3 °C). Nights average below 18 °C in every month of the season, from 3.4 °C to 16.1 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	21.6	9.5	52	9	14:35
June	26.9	13.9	43	8	15:17
July	30.1	15.8	15	4	15:00
August	30.6	16.1	18	4	13:56
September	25.2	13.2	31	6	12:32
October	20.7	9.9	53	8	11:07
November	13.5	5.7	70	12	9:48
December	10.3	3.4	49	10	9:05

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Logroño, Tudela is 22 days earlier and San Sebastián 11 days later.

City	Distance	Date	Difference
Vitoria-Gasteiz	46 km	4 June – 15 August	7 days later
Pamplona	76 km	1 June – 21 August	4 days later
Soria	79 km	30 May – 31 July	2 days later
Tudela	82 km	6 May – 28 August	22 days earlier
Bilbao	96 km	2 June – 16 September	5 days later
San Sebastián	102 km	8 June – 24 August	11 days later

Where to buy watermelon plants and seeds near Logroño

Buy plants ready to set out from 28 May to 25 August (from 7 May to 25 August for an unheated greenhouse); seed for raising your own is sown from 9 April to 28 July. Within 15 km of Logroño OpenStreetMap lists 1 garden centre and 3 markets (collected 27 October 2026).

Plaza de Abastos - Mercado de San Blas — market
Sat 07:30–14:00; Mon–Fri 07:30–14:00, 16:00–20:00 · 1 km
Espacios Verdes — garden centre
2 km
Mercado del Corregidor — market
1 km
Mercado de Patricia — market
2 km

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.

Questions