When to plant watermelons in Kitakyushu: from 15 May

In Kitakyushu, watermelon: sow for seedlings from 27 March; plant into a greenhouse from 24 April; plant out into open ground from 15 May. There is no autumn frost here, so the frost dates set no end to the window.

Watermelon in Kitakyushu: soil, season and weather

In Kitakyushu the soil, not frost, sets the date: the last frost is over around 17 February, but the top 7 cm of soil reaches 18 °C — the minimum on the watermelon card — only around 15 May, 87 days later. Kitakyushu has no autumn frost in the median year, so frost does not end the season.

Last spring frost	17 February
Top 7 cm of soil at 18 °C	15 May, 87 days after the last frost
Into an unheated greenhouse	from 24 April; April outside: 11.4 °C at night, 18 °C by day; card 18–35 °C
Days in the bed to the first harvest (card)	59
First harvest, if planted in this window	from 13 July
Daylight	13:05 on 17 April, 13:54 on 15 May
Watering outdoors when fruiting (card)	every 5 days; the driest month, October, has 9 rainy days

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

Watermelon in Kitakyushu: care after planting

Planted on 15 May: in the first weeks water every 5 days.

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

15 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 Kitakyushu during the watermelon season

No month of the season averages above the watermelon card's 18–35 °C by day; the warmest, August, averages 31.1 °C. Nights average below 18 °C in May (15.6 °C) and October (17 °C).

Month	Day, °C	Night, °C	Rain, mm	Rainy days	Daylight on the 15th
May	21.8	15.6	163	11	13:54
June	25.4	19.8	260	14	14:24
July	29.3	24.4	261	16	14:12
August	31.1	25.5	240	12	13:26
September	27.7	22.5	213	14	12:25
October	22.5	17	100	9	11:23

ERA5 2016–2025, Open-Meteo

Watermelon in nearby cities

Around Kitakyushu, Kumamoto is 13 days earlier and Hiroshima 11 days later.

City	Distance	Date	Difference
Fukuoka	55 km	5 May – 11 September	10 days earlier
Kumamoto	121 km	2 May – 24 August	13 days earlier
Hiroshima	155 km	26 May – 16 August	11 days later
Busan	220 km	15 May – 13 August	same day
Ulsan	234 km	18 May – 7 August	3 days later
Kagoshima	255 km	6 May – 16 September	9 days earlier

Where to buy watermelon plants and seeds near Kitakyushu

Buy plants ready to set out from 15 May (from 24 April for an unheated greenhouse); seed for raising your own is sown from 27 March. Within 15 km of Kitakyushu OpenStreetMap lists 1 garden centre and 3 markets (collected 28 October 2026).

ガーデニングshop やまもと — garden centre
15 km
Karato Wholesale Market — market
11 km · karatoichiba.com
Tanga Ichiba — market
0 km
中央卸売市場 — market
3 km

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