After the slow start, growing degree days (GDDs) are accumulating fast with warm weather. See the AAFC maps for GDDs accumulated across the Prairies up to May 13 and up to May 20. Click here to create other AAFC weather maps. GDDs are calculated by averaging daily maximum and daily minimum temperatures for each day, and subtracting the assumed minimum temperature (Base T) required for growth to proceed. Canola GDDs outline in the table below are based on a Base 0°C. A day with a high of 20°C and a low of 10°C would contribute 15 GDDs on a Base 0 scale.
Accumulated GDDs to date (as shown on the AAFC maps) would not count toward canola seeded today. Napus seeded today would need roughly another 1,500 GDDs before frost to reach maturity.