Winter in Winterthur is quite chilly, with January being the coldest month, averaging around 0°C. Mornings often start below freezing, but temperatures can rise significantly during the day. Spring arrives slowly, with March and April temperatures gradually warming up to average highs of around 8°C. Summer brings pleasant weather, with July and August averaging a comfortable 18-19°C, while September still enjoys warm days, albeit slightly cooler nights. Autumn is marked by a return to cooler temperatures, with October's mornings often near freezing again.