Red River Valley, MB, Canada / Canola (Altona)
Total GDD:
3505
(Sep 30)
Day 153 / 153 (100%)
Current Season
Total GDD:
3505
(Sep 30)
Method: 41°F
7-Day Daily Avg: 21.8
7-Day Projection: 3658 by Oct 07
Season: May 01, 25 - Sep 30, 2025
Key Freeze Dates (28°F)
Last Freeze:
10%: 04-20
50%: 05-06
90%: 05-15
10%: 04-20
50%: 05-06
90%: 05-15
First Freeze:
10%: 09-22
50%: 10-07
90%: 10-21
10%: 09-22
50%: 10-07
90%: 10-21
Growing Degree Days (GDD) track heat accumulation to predict when plants reach growth stages, pests emerge, and diseases become active.
Thresholds mark specific GDD values when events typically occur, with crossing dates showing when your season reaches each milestone.
Thresholds & Notes
Emergence
150
°D
May 10, 2025
|
May 12, 2024
|
May 12, 2023
Growth Stage
Cotyledons visible. Flea beetle scouting critical - threshold 25% leaf area loss.
2-Leaf (Rosette)
300
°D
May 15, 2025
|
May 23, 2024
|
May 19, 2023
Growth Stage
First true leaves. Frost tolerant to 28°F at this stage.
4-Leaf
475
°D
May 28, 2025
|
Jun 3, 2024
|
May 27, 2023
Growth Stage
Rosette expanding. Herbicide timing window for broadleaf weeds.
6-Leaf (Late Rosette)
650
°D
Jun 4, 2025
|
Jun 13, 2024
|
Jun 2, 2023
Growth Stage
Bolting imminent. Final fungicide timing for blackleg if needed.
Bolting
850
°D
Jun 14, 2025
|
Jun 22, 2024
|
Jun 7, 2023
Growth Stage
Stem elongation begins. Plant commits to reproductive growth.
Bud Formation
1000
°D
Jun 20, 2025
|
Jun 28, 2024
|
Jun 13, 2023
Growth Stage
Green buds visible, still enclosed. Sclerotinia scouting begins.
First Flower
1200
°D
Jun 28, 2025
|
Jul 7, 2024
|
Jun 20, 2023
Growth Stage
10% bloom. Sclerotinia fungicide window opens (20-50% bloom). Most frost-sensitive stage.
Full Flower
1450
°D
Jul 7, 2025
|
Jul 15, 2024
|
Jun 29, 2023
Growth Stage
50%+ bloom. Peak pollinator activity. Heat stress above 86°F reduces pod set.
End of Flower
1850
°D
Jul 23, 2025
|
Jul 29, 2024
|
Jul 16, 2023
Growth Stage
Petals dropping. Pod fill begins. Lygus bug threshold 10-20/10 sweeps.
Pod Development
2300
°D
Aug 9, 2025
|
Aug 15, 2024
|
Aug 2, 2023
Growth Stage
Seeds visible in pods. Maintain moisture for seed fill. Green seed risk if frost hits now.
Seed Color Change
2800
°D
Aug 29, 2025
|
Sep 3, 2024
|
Aug 22, 2023
Growth Stage
Swath timing. Seeds firm, roll but don't crush. Comfortable margin before Sept 27 hard freeze.
Harvest Ready
3000
°D
Sep 9, 2025
|
Sep 12, 2024
|
Aug 30, 2023
Growth Stage
<10% seed moisture for straight-cut. Red River Valley delivers ~3,485 GDD by Sept 27 (10% freeze).