Frost Dates for Rock River, YT

Frost Dates

Last Spring Frost (50%) iA 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. June 10
First Fall Frost (50%) iA 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. August 9
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

30% Probability iOnly a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.

Last Spring Frost June 16
First Fall Frost July 28

Hard Freeze (−2°C)

Last Spring Hard Freeze May 30
First Fall Hard Freeze September 2
66.98°N, -136.22°W © OpenStreetMap

Growing Season

60 Days June 10 to August 9

USDA Hardiness Zone iHardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.

Zone 4a

Avg. annual minimum: −30 to −25°F (−34 to −32°C)

Learn more

Köppen Climate iThe Köppen climate classification system categorizes climates based on temperature and precipitation patterns.

Dfc Subarctic

Short, cool summers and long, very cold winters. Growing seasons of 3–4 months require fast-maturing varieties. Root vegetables, potatoes, and cold-hardy greens are the most reliable.

Köppen climate map

Temperature

-25° -10° 5° 20°
-19°
High: -16°C
Avg: -19°C
Low: -23°C
Jan
-17°
High: -13°C
Avg: -17°C
Low: -21°C
Feb
-16°
High: -12°C
Avg: -16°C
Low: -20°C
Mar
-8°
High: -4°C
Avg: -8°C
Low: -12°C
Apr
3°
High: 7°C
Avg: 3°C
Low: -2°C
May
11°
High: 16°C
Avg: 11°C
Low: 6°C
Jun
12°
High: 17°C
Avg: 12°C
Low: 8°C
Jul
9°
High: 13°C
Avg: 9°C
Low: 5°C
Aug
3°
High: 6°C
Avg: 3°C
Low: -1°C
Sep
-6°
High: -4°C
Avg: -6°C
Low: -9°C
Oct
-15°
High: -12°C
Avg: -15°C
Low: -18°C
Nov
-17°
High: -14°C
Avg: -17°C
Low: -21°C
Dec
0°C
−2°C
Avg High Avg Temp Avg Low Light Frost (0°C) Hard Frost (−2°C)

Precipitation

0 mm 30 mm 60 mm 90 mm
0 mm
0.0 mm
Jan
0 mm
0.0 mm
Feb
0 mm
0.0 mm
Mar
0 mm
0.0 mm
Apr
8 mm
7.6 mm
May
30 mm
30.5 mm
Jun
71 mm
71.1 mm
Jul
99 mm
99.1 mm
Aug
53 mm
53.3 mm
Sep
3 mm
2.5 mm
Oct
0 mm
0.0 mm
Nov
0 mm
0.0 mm
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec3h7.5h11h15h19h24h21h16.5h12.5h9h4.5h0h
Jan: 10:26 AM – 1:34 PM · 3h 09m
Feb: 8:15 AM – 3:45 PM · 7h 30m
Mar: 6:27 AM – 5:33 PM · 11h 07m
Apr: 4:28 AM – 7:32 PM · 15h 04m
May: 2:27 AM – 9:33 PM · 19h 06m
Jun: 24h (Midnight Sun)
Jul: 1:27 AM – 10:33 PM · 21h 05m
Aug: 3:39 AM – 8:21 PM · 16h 42m
Sep: 5:39 AM – 6:21 PM · 12h 42m
Oct: 7:34 AM – 4:26 PM · 8h 52m
Nov: 9:39 AM – 2:21 PM · 4h 41m
Dec: 0h (Polar Night)
Daylight Longest: 24h 00m · Shortest: 0h 00m

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