Frost dates for Portland

◇ Station-based · 89/100 confidence

Last spring frost · safe

May 11

~10% frost risk · typical May 1

First fall frost · safe

Oct 1

~10% frost risk · typical Oct 10

Frost-free days

165

May 1 → Oct 10

Climate zone

Continental, warm summer

Köppen Dfb

The 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

FROST

GROWING SEASON — 165 DAYS

MAY 1

OCT 10