When to plant watermelons in Paysandú: 21 September – 17 March

In Paysandú, watermelon: sow for seedlings from 3 August to 18 February; plant into a greenhouse from 31 August to 17 March; plant out into open ground from 21 September to 17 March.

Watermelon in Paysandú: soil, season and weather

In Paysandú the soil, not frost, sets the date: the last frost is over around 15 July, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 21 September, 68 days later.

Last spring frost	15 July
Top 7 cm of soil at 18 °C	21 September, 68 days after the last frost
Into an unheated greenhouse	31 August – 17 March; August outside: 8.8 °C at night, 18.9 °C by day; card 18–35 °C
First autumn frost	26 June, 279 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	19 November – 15 May
Days left for picking	220
Daylight	11:10 on 24 August, 12:04 on 21 September
Watering outdoors when fruiting (card)	every 5 days; the driest month, June, has 7 rainy days

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

Watermelon in Paysandú: care after planting

Planted on 21 September: in the first weeks water every 5 days.

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

21 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 Paysandú during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, January, averages 30.8 °C. Months that stay below 18 °C even by day on average: June (17 °C). Nights average below 18 °C in March–June and September–November (8.3–17.8 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
September	20.8	10.7	91	8	11:52
October	23.7	13.1	104	9	12:51
November	27.5	15.9	84	7	13:46
December	29.5	18.2	110	8	14:15
January	30.8	20.4	126	8	14:02
February	29.8	19.8	131	8	13:14
March	27.4	17.8	107	9	12:19
April	23.6	14.7	155	9	11:19
May	19.2	11.1	93	8	10:29
June	17	8.3	74	7	10:02

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Paysandú, Salto is 30 days earlier and Colonia del Sacramento 24 days later.

City	Distance	Date	Difference
Salto	105 km	from 22 August	30 days earlier
Tacuarembó	209 km	14 October – 4 March	23 days later
Paraná	240 km	from 10 September	11 days earlier
Colonia del Sacramento	240 km	from 15 October	24 days later
Rosario	250 km	29 September – 5 March	8 days later
Buenos Aires	255 km	from 7 October	16 days later

Where to buy watermelon plants and seeds near Paysandú

Buy plants ready to set out from 21 September to 17 March (from 31 August to 17 March for an unheated greenhouse); seed for raising your own is sown from 3 August to 18 February. Within 15 km of Paysandú OpenStreetMap lists 1 market (collected 27 October 2026).

Mercado Municipal — market
1 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