August continued to cool down day by day during the third week of the month, but it was still on the wet side. The overall temperature dropped another full degree, and although precipitation in Ormstown eased off from previous weeks, the many and varied thunderstorms continued to dump heavy rainfall on a very localized basis.
Rainfall for the first three weeks of the month totalled 101 millimetres at the farm in Ormstown, which is about 170 per cent of normal and already well in excess of a full month of precipitation (84 mm). Combined with the last three days of July, the Valley has received at least 170 mm of precipitation in just over three weeks – which is two months’ worth! In comparison, the Environment Canada weather station in Sainte-Anne-de-Bellevue received just 98 mm in the same period.
Temperatures continued to be warm, but the air in the last week has been less humid. The average temperature for three weeks in August is 20.9 degrees Celsius, down from 21.7 C the week before, but still above the normal for the entire month of 20.2 C.
In lockstep with the above-average temperature, the corn heat unit (CHU) count continued to climb with 563 CHU for the first 22 days. Compared to the prorated calculation of 545 CHU, the month is well on its way to reaching the normal for August of 768 CHU. The total so far for the season (since May 16) is now 2406 CHU, or about 72 per cent of normal.
The remainder of August is forecast to be slightly cooler than average during the day and slightly warmer at night. There will be shower and thundershower activity for the last couple of days and continuing into the first few days of September, which will be normal for temperature but with much less rain in the forecast once the first week is out of the way.