The first half of August brought a string of powerful thunderstorms and wetter-than-expected conditions to the Châteauguay Valley, leaving localized damage on farms and residential neighbourhoods while nudging temperatures slightly above seasonal averages.
Storms, hail and power outages
Several storm cells that tracked across the Valley early in the week caused significant local impacts: trees were uprooted, branches littered streets and some neighbourhoods experienced extended power outages. Fruit growers on Covey Hill reported a notable hail event that damaged apple crops.
"The Valley has received at least 140 mm of precipitation in just over two weeks."
That rainfall total combines the first two weeks of August with the final three days of July, illustrating how concentrated precipitation was over a short period.
Rainfall and temperature figures
Rainfall measured at a farm in Ormstown reached 83 millimetres during the first two weeks of August — equivalent to roughly a full month of normal precipitation for that location. By contrast, the Environment Canada station at Sainte‑Anne‑de‑Bellevue recorded a notably lower 64 mm over the same interval, underlining how variable conditions were even across neighbouring communities.
| Measure | Value |
|---|---|
| Ormstown rainfall (first 2 weeks of Aug) | 83 mm |
| Sainte‑Anne‑de‑Bellevue rainfall (same period) | 64 mm |
| Combined late July–mid Aug (Valley) | ≥ 140 mm |
| Average temperature (first half of August) | 21.7 °C (about 1.5 °C above normal) |
Temperatures remained warm and humid overall. The average for the period was 21.7 °C, compared with a historical normal of 20.2 °C for August. That modest positive anomaly has implications for both growers and the pace of crop development.
Crop development and heat units
Measurements of corn heat units (CHUs) — a metric used by farmers to assess crop maturity — continued to climb. The Valley logged 400 CHU for the first 15 days of August, ahead of a prorated expectation of 372 CHU. Based on that pace, the month is on track to approach the August normal of 768 CHU.
For the season stretching back to May 16, the total CHU is now 2,243, which represents about 65 per cent of the normal seasonal accumulation. That figure gives farmers a sense of the remaining growing-season heat needed for late-maturing crops.
Outlook for the rest of August
Forecasts for the remainder of August point to days that will be slightly cooler than average and nights a bit warmer, with intermittent showers and thunderstorm activity through mid‑month. Local variability remains a clear theme: some sectors of the Valley saw heavy, damaging storms while neighbouring areas received more typical amounts of rain.
- Localized severe storms produced tree damage and power outages.
- Covey Hill apple growers reported significant hail damage.
- Rainfall totals were uneven across the region, with Ormstown notably wetter than Sainte‑Anne‑de‑Bellevue.
For Chateauguay residents, the key takeaway is that the early-August pattern combined above‑average warmth with concentrated precipitation events — a mix that has immediate consequences for outdoor repairs, farm recovery and preparations for the remainder of the growing season.
