When to plant watermelons in San Rafael: 22 September – 24 February

In San Rafael, watermelon: sow for seedlings from 4 August to 27 January; plant into a greenhouse from 1 September to 24 February; plant out into open ground from 22 September to 24 February. For plants and seeds, the places nearby include Vivero Cedro Azul (garden centre, 2 km); addresses and opening hours are below.

Watermelon in San Rafael: soil, season and weather

In San Rafael the soil, not frost, sets the date: the last frost is over around 23 August, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 22 September, 30 days later.

Last spring frost	23 August
Top 7 cm of soil at 18 °C	22 September, 30 days after the last frost
Into an unheated greenhouse	1 September – 24 February; September outside: 7.4 °C at night, 21.4 °C by day; card 18–35 °C
First autumn frost	4 June, 256 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	20 November – 23 April
Days left for picking	197
Daylight	11:07 on 25 August, 12:06 on 22 September
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 2 rainy days

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

Watermelon in San Rafael: care after planting

Planted on 22 September: in the first weeks water every 5 days.

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

22 September — 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 San Rafael during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 31.6 °C. Months that stay below 18 °C even by day on average: May (17.1 °C) and June (14.4 °C). Nights average below 18 °C in March–June and September–December (2.8–17.3 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
September	21.4	7.4	12	2	11:51
October	24.2	10.3	47	5	12:55
November	28.3	14.5	32	5	13:55
December	31	17.3	26	5	14:27
January	31.6	19	52	8	14:13
February	30.4	18	44	7	13:21
March	26.9	14.9	35	5	12:20
April	22	10.7	29	4	11:14
May	17.1	6.6	32	5	10:20
June	14.4	2.8	9	2	9:51

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around San Rafael, Mendoza is 3 days earlier and Rancagua 45 days later.

City	Distance	Date	Difference
Mendoza	198 km	19 September – 7 March	3 days earlier
Rancagua	226 km	6 November – 2 March	45 days later
San Luis	238 km	25 September – 13 March	3 days later
Santiago	251 km	14 October – 8 March	22 days later
Curicó	268 km	31 October – 26 February	39 days later
Talca	314 km	6 November – 3 March	45 days later

Where to buy watermelon plants and seeds near San Rafael

Buy plants ready to set out from 22 September to 24 February (from 1 September to 24 February for an unheated greenhouse); seed for raising your own is sown from 4 August to 27 January. Within 15 km of San Rafael OpenStreetMap lists 1 garden centre, 1 market and 1 farm shop (collected 28 October 2026).

Vivero Cedro Azul — garden centre
Marcelino Champagnat 435, 5600 · 2 km
La Lili — market
Lassa, 5600 · Tue–Sun 09:00–21:00 · 7 km
Finca Rubio — farm shop
11 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.

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