When to plant watermelons in Cleveland: 28 May – 12 August

In Cleveland, watermelon: sow for seedlings from 9 April to 15 July; plant into a greenhouse from 7 May to 12 August; plant out into open ground from 28 May to 12 August.

Watermelon in Cleveland: soil, season and weather

In Cleveland the soil, not frost, sets the date: the last frost is over around 9 April, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 28 May, 49 days later.

Last spring frost	9 April
Top 7 cm of soil at 18 °C	28 May, 49 days after the last frost
Into an unheated greenhouse	7 May – 12 August; May outside: 11.4 °C at night, 19 °C by day; card 18–35 °C
First autumn frost	21 November, 177 days after the start
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	26 July – 10 October
Days left for picking	118
Daylight	13:57 on 30 April, 14:53 on 28 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, September, has 10 rainy days

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

Watermelon in Cleveland: 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 Cleveland during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, July, averages 26.6 °C. Months that stay below 18 °C even by day on average: October (17.6 °C) and November (10.1 °C). Nights average below 18 °C in May, June and September–November (4.1–17.2 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	19	11.4	109	13	14:30
June	24.4	17.2	106	13	15:10
July	26.6	20.2	124	14	14:54
August	25.7	19.6	95	13	13:53
September	23.2	16.7	77	10	12:31
October	17.6	11	104	13	11:09
November	10.1	4.1	88	13	9:53

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Cleveland, Toledo (United States) is 4 days earlier and Erie 2 days later.

City	Distance	Date	Difference
Windsor	141 km	27 May – 29 July	1 day earlier
Detroit	145 km	27 May – 29 July	1 day earlier
Erie	151 km	30 May – 10 August	2 days later
Toledo (United States)	154 km	24 May – 29 July	4 days earlier
London (Canada)	169 km	29 May – 29 July	1 day later
Pittsburgh	185 km	26 May – 31 July	2 days earlier

Where to buy watermelon plants and seeds near Cleveland

Buy plants ready to set out from 28 May to 12 August (from 7 May to 12 August for an unheated greenhouse); seed for raising your own is sown from 9 April to 15 July. Within 15 km of Cleveland OpenStreetMap lists 9 garden centres and 8 markets (collected 20 October 2026).

Rosby's — garden centre
9 km
Wake Forest Garden Center — garden centre
14 km
STUMP — garden centre
14 km
Produce Arcade — 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