Lethbridge residents can look forward to an unseasonably warm start to the week, with Environment Canada forecasting sunny skies and daytime highs climbing to 29°C on Monday, September 21, 2026. That is about 11 degrees above the seasonal normal high of 18°C for late September.
The warm spell is expected to continue through Wednesday, giving people a good chance to finish outdoor chores or enjoy activities before conditions change later in the week. By Saturday, September 26, highs are forecast to drop to around 15°C under a mix of sun and cloud.
According to Environment Canada, Friday night brings a 30 percent chance of showers with an overnight low of 3°C, signalling a shift toward cooler, cloudier weather into the following week.
The warm temperatures are part of a larger pattern linked to an exceptional El Niño event that is expected to bring an extended fall season to much of Canada, including Alberta.
With sunrise at 7:16 a.m. and sunset at 7:32 p.m. on Monday, Lethbridge is getting noticeably shorter days, but the week ahead is a good time to enjoy the remaining warm weather before autumn conditions settle in.
