When to plant watermelons in Copiapó: 8 September – 14 March

In Copiapó, watermelon: sow for seedlings from 21 July to 15 February; plant into a greenhouse from 18 August to 14 March; plant out into open ground from 8 September to 14 March.

Watermelon in Copiapó: soil, season and weather

In Copiapó the soil, not frost, sets the date: the last frost is over around 19 July, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 8 September, 51 days later.

Last spring frost	19 July
Top 7 cm of soil at 18 °C	8 September, 51 days after the last frost
Into an unheated greenhouse	18 August – 14 March; August outside: 8.6 °C at night, 19.3 °C by day; card 18–35 °C
First autumn frost	23 June, 289 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	6 November – 12 May
Days left for picking	230
Daylight	11:02 on 11 August, 11:43 on 8 September
Watering outdoors when fruiting (card)	every 5 days; the driest month, November, has 0 rainy days

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

Watermelon in Copiapó: care after planting

Planted on 8 September: in the first weeks water every 5 days.

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

8 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 Copiapó during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, February, averages 23.7 °C. Nights average below 18 °C in every month of the season, from 8.1 °C to 13.7 °C.

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
September	20.2	9.6	1	0	11:54
October	21.1	10.7	1	0	12:43
November	21.7	11.5	0	0	13:28
December	22.6	12.2	0	0	13:51
January	23.4	13.3	2	0	13:41
February	23.7	13.7	0	0	13:02
March	23	13.5	0	0	12:17
April	21.1	11.9	6	0	11:27
May	19.6	10.4	5	1	10:47
June	18.3	8.1	5	1	10:25

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Copiapó, La Rioja is 9 days earlier and Salta 18 days later.

City	Distance	Date	Difference
La Rioja	408 km	30 August – 5 March	9 days earlier
San Fernando del Valle de Catamarca	463 km	30 August – 19 March	9 days earlier
San Juan	495 km	18 September – 10 March	10 days later
San Miguel de Tucumán	510 km	from 15 September	7 days later
Calama	564 km	from 9 September	1 day later
Salta	569 km	26 September – 20 March	18 days later

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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