September ended up being cool and dry. The average temperature was 15.7 degrees Celsius, a full half-degree below the normal of 16.2 C. The overall coolness was largely due to some quite cold nights in the last third of the month, which included two nights when the ground temperature dipped below zero.
Despite the cooler temperatures, the corn heat unit (CHU) count kept pace with 545 CHU total for the month, just a shade below normal at 559 CHU. The total for the season so far (since May 16) is now 3,154 CHU, again very close to the normal of 3,189 CHU.
The wetness of the preceding summer months disappeared, with only 59 millimetres of rain for the month, which is only 65 per cent of normal. This dry spell was largely offset by the 21 mm of rain received in the first few days of October, which was welcome, but will ideally not set the stage for another wet month as farmers get to work on the soybean and corn harvests.
So far in 2026, the average temperature is only 0.2 C above average and precipitation is now just a wee bit below normal (81 mm versus 83 mm average per month). Remember, despite a wet summer, January, February, May and now September were all below average for precipitation.
The cropping season was, however, a different story, with 100 mm of rain, or 20 per cent above average. Typically, there 20 to 30 days a year when the daytime high is 30 C or higher, but in 2026 there were only 10 days of hot weather. To offset this “coolness,” nighttime temperatures were generally above average, particularly in August.
The forecast for October is for below-average temperatures, in particular during the daytime, with a period of precipitation before the middle of the month but a dry second half.