Sudbury's winters are harsh, with temperatures often plummeting below -20°C in January and February, but gradually warming up by March. Spring is a slow process, with April and May seeing mild temperatures range from around -5°C to over 25°C, creating a wide temperature swing. Summer months of June, July, and August bring relatively stable warmth, with average highs consistently above 18°C. Autumn sees a return to cooler temperatures, with September and October experiencing dips below freezing, while November is marked by significant cold snaps. Frosts are common throughout the year, but December's temperatures can be quite chilly, dipping as low as -23°C.