Excellent question that we usually do not have to think about in early May!
As most grain is still cold in the bin and with the rapid increase in outside temperature, the potential for spoilage could still occur in stored canola and flax still in the bin from 2015 harvest.
If you think this might be an issues, check what is the seed moisture and the temperature is again. The 5C, 8.5% moisture canola in March had no risk of spoilage, but a 35C, 8.5% moisture canola does. Flax is susceptible to spoilage as well, if the grain gets very warm in the bin and the moisture is over 8%. If things are all good today, check in a couple of days again if the May heat wave continues and consider turning on the aeration fan and open up the bin hatch at the top of the bin to let humidity escape.
This question came in as a concern over the potential of condensation to form on the bin walls from the hot outside air hitting the cold grain in the bin. Aeration could be used as a tool with the hot, but very dry air to warm the grain slowly and move some of the potential humidity out through the top vent or hatch. Monitoring though is key and should continue until the grain is delivered to catch spoilage issues. A great resource on more about aeration and grain in storage can be found on the PAMI (Prairie Agricultural Machinery Institute) website www.pami.ca/crops/storage and at the Canadian Grains Commission https://www.grainscanada.gc.ca/storage-entrepose/ssg-de-eng.htm
Submitted by Anastasia Kubinec, Oilseed Crop Specialist, Manitoba Agriculture