Winters in Saint-Nazaire are cool and occasionally chilly, with temperatures ranging from around -6°C to a relatively mild 13°C on average. The coldest months are January and February, but even then the temperature rarely drops below freezing. As spring approaches, temperatures gradually rise, with March and April averaging around 9-10°C. Summer is warm and pleasant, with July typically being the hottest month, while September can still be quite warm before autumn sets in. In autumn and winter, temperatures tend to drop again, but are generally milder than during the coldest months of the year.