When to plant melon (cantaloupe/watermelon) in Missoula

Melon (cantaloupe/watermelon) is frost-tender, so every date keys off Missoula's last spring frost of May 15.
Step 1 · Sow
Start seeds indoors
May 5 – May 26
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Jul 27 – Aug 17
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Oct 10 – Nov 4
Picking runs until conditions turn against the crop.
Window
Days to maturity
75 – 100 d
Missoula's 138-day season leaves this much room.
Melon (cantaloupe/watermelon) on Missoula'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 15
OCT 4

Common questions

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

Direct-sow around late July (Jul 27–Aug 17) in Missoula, based on its local frost dates. Confidence 81%.

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

Expect to harvest from around early October (Oct 10–Nov 4) in Missoula, based on its local frost dates. Confidence 75%.

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

Start seeds indoors around early May (May 5–May 26) in Missoula, based on its local frost dates. Confidence 79%.

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

Transplant outdoors around late July (Jul 27–Aug 17) in Missoula, based on its local frost dates. Confidence 81%.

How long is the growing season in Missoula?

Missoula has roughly 138 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 Missoula's frost dates.

Confidence 83/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.