When to plant melon (cantaloupe/watermelon) in Sapporo

Melon (cantaloupe/watermelon) is frost-tender, so every date keys off Sapporo's last spring frost of May 12.
Step 1 · Sow
Start seeds indoors
Apr 28 – May 19
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Aug 10 – Aug 31
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Oct 24 – Nov 18
Picking runs until conditions turn against the crop.
Window
Days to maturity
75 – 100 d
Sapporo's 166-day season leaves this much room.
Melon (cantaloupe/watermelon) on Sapporo's growing year
Frost-bounded season with crops mapped onto the 12-month axis.
Frost risk Growing Harvest
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
MAY 12
OCT 20

Common questions

When can I sow melon (cantaloupe/watermelon) outdoors in Sapporo?

Direct-sow around early August (Aug 10–Aug 31) in Sapporo, based on its local frost dates. Confidence 44%.

When will melon (cantaloupe/watermelon) be ready to harvest in Sapporo?

Expect to harvest from around late October (Oct 24–Nov 18) in Sapporo, based on its local frost dates. Confidence 40%.

When should I start melon (cantaloupe/watermelon) seeds indoors in Sapporo?

Start seeds indoors around late April (Apr 28–May 19) in Sapporo, based on its local frost dates. Confidence 43%.

When can I transplant melon (cantaloupe/watermelon) outdoors in Sapporo?

Transplant outdoors around early August (Aug 10–Aug 31) in Sapporo, based on its local frost dates. Confidence 44%.

How long is the growing season in Sapporo?

Sapporo has roughly 166 frost-free days, which is enough time to grow melon (cantaloupe/watermelon) to maturity outdoors.

The rule of thumb

Sow melon (cantaloupe/watermelon) 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. Every date on this page is derived from that rule and Sapporo's frost dates.

Confidence 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.