Calgary's winters are bitterly cold, with temperatures often dropping below -20°C and occasionally plummeting as low as -42°C in February. The spring months bring a gradual warming trend, with daytime highs reaching into the teens by April and May. Summer is mild, with July and August averaging around 19°C, although occasional heatwaves can push temperatures above 30°C. Autumn is similar to spring, with a slow cooling trend that brings temperatures back down into single digits by November. Overall, Calgary's temperature fluctuations are quite extreme, with a wide range of highs and lows across the year.