When to plant watermelons in Guadalajara (Spain): 17 May – 15 August

In Guadalajara (Spain), watermelon: sow for seedlings from 29 March to 18 July; plant into a greenhouse from 26 April to 15 August; plant out into open ground from 17 May to 15 August.

Watermelon in Guadalajara (Spain): soil, season and weather

In Guadalajara (Spain) the soil, not frost, sets the date: the last frost is over around 25 March, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 17 May, 53 days later.

Last spring frost	25 March
Top 7 cm of soil at 18 °C	17 May, 53 days after the last frost
Into an unheated greenhouse	26 April – 15 August; April outside: 5.8 °C at night, 17.8 °C by day; card 18–35 °C
First autumn frost	24 November, 191 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	15 July – 13 October
Days left for picking	132
Daylight	13:26 on 19 April, 14:29 on 17 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, July, has 1 rainy day

The same dates in Guadalajara (Spain) hold for Cucumber, Bell Pepper, Eggplant, Zucchini and Pumpkin.

Watermelon in Guadalajara (Spain): care after planting

Planted on 17 May: in the first weeks water every 5 days.

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

17 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 Guadalajara (Spain) during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 32.9 °C. Months that stay below 18 °C even by day on average: November (13.7 °C). Nights average below 18 °C in May–July and September–November (4.4–17.9 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	22.5	9.5	42	8	14:26
June	28.3	14.6	32	6	15:04
July	32.9	17.9	6	1	14:49
August	32.5	18	12	1	13:49
September	25.9	13.3	47	6	12:30
October	20.9	9.5	77	9	11:11
November	13.7	4.4	52	9	9:57

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Guadalajara (Spain), Toledo is 6 days earlier and Segovia 15 days later.

City	Distance	Date	Difference
Madrid	51 km	14 May – 18 August	3 days earlier
Segovia	88 km	1 June – 30 July	15 days later
Cuenca (Spain)	107 km	14 May – 4 August	3 days earlier
Toledo	113 km	11 May – 27 August	6 days earlier
Aranda de Duero	124 km	31 May – 4 August	14 days later
Ávila	130 km	31 May – 8 August	14 days later

Where to buy watermelon plants and seeds near Guadalajara (Spain)

Buy plants ready to set out from 17 May to 15 August (from 26 April to 15 August for an unheated greenhouse); seed for raising your own is sown from 29 March to 18 July. Within 15 km of Guadalajara (Spain) OpenStreetMap lists 3 garden centres, 1 plant nursery and 2 markets (collected 27 October 2026).

Huerta del Sotillo — garden centre
2 km · huertadelsotillo.com
Viveros Sanchez — garden centre
5 km
Botanie Garden Center — garden centre
5 km
El Serranillo — plant nursery
4 km · miteco.gob.es

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