Rocky Mountain House is getting a taste of late summer this week, with Environment Canada forecasting sunny skies and a high of 27°C on Monday. That’s 12 degrees above the seasonal normal of 15°C for this time of year.
According to Environment Canada, the warm spell is expected to continue through Tuesday, but residents should not get too comfortable. An overnight low of about 4°C tonight brings a risk of frost, which could damage tender garden plants like tomatoes, peppers, and beans. Tuesday night is expected to be clear with a low of 4°C, with overnight lows dropping to 2°C by Friday night.
A cooling trend begins Thursday, with cloudy skies and a high of 14°C. By Friday, rain is likely with a high of only 8°C, and Friday night brings cloudy conditions with a 60% chance of showers and a low of 2°C.
The brief warm-up fits the pattern of what is often called an Indian Summer, though it does not fully meet the traditional definition of at least seven consecutive days above 21°C after the fall equinox. Still, for those with outdoor plans or unfinished garden tasks, the first half of the week is the time to act.
Gardeners should cover or bring in sensitive plants before tonight to protect them from the frost, as the growing season is winding down. The warm days and cold nights are typical of autumn in Alberta, where clear skies allow heat to escape quickly after sunset.