45.4200°N/75.7000°W
When to plant in Ottawa
Ontario, Canada · Continental, warm summer (Köppen Dfb)
Last spring frost · safe
May 11
~10% frost risk · typical Apr 29
First fall frost · safe
Sep 29
~10% frost risk · typical Oct 8
Frost-free days
161
Apr 29 → Oct 8
Climate zone
Continental, warm summer
Köppen Dfb
89/100 confidence
◇ Station-based
The frost date shown is the safe date (~10% frost risk); the typical median is shown alongside. Your microclimate can shift things ±1–2 weeks.
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
FROST
GROWING SEASON — 161 DAYS
APR 29
OCT 8
Full crop calendar
Source: Curated · based on NOAA GHCN-Daily 1991–2020 normal · Köppen–Geiger classification (Beck et al. 2023) · crop windows from FAO ECOCROP references. How we calculate this →
Also see frost dates for Ottawa.