We may just be a few days into October here in Calgary, but the forecast is showing a big cooling trend before a nice temperature boost appears. According to the Environment and Climate Change Canada (ECCC) forecast, the weather in Calgary is above average as we wrap up the workweek, but things are expected to take a turn over the weekend. Calgary is forecast to reach a high of 18°C today, with an overnight low of 6°C and a slight chance of showers. When you do the math between tomorrow’s overnight low and the high on Wednesday, it’s a temperature change of 21 degrees. According to ECCC, the average high temperature for Calgary around this time of year is 15°C, while the average low temperature is 1°C.