Florence’s tourist season peaks during the summer when the weather is hot (above 30°C or 86°F) and even nights don’t usually get below 25°C (75°F).
Heat waves do hit the city leading to 35°C+ (95°F+) temperatures occasionally and in rare cases up to 40°C (104°F). The record high is 42°C (108°F). The least amount of precipitation also falls during the summer. Winters are wet and chilly but not as cold as cities in the Po Valley. Lows usually hover between 0°C (32°F) and 5°C (42°F) and highs are around 10°C (50°F).
Temperatures can drop below -5°C (23°F) when Italy is hit by a cold wave and, in rare cases, below -10°C (12°F). The record low is -23°C (-9°F). For those coming to the city seeking to see snow, keep in mind that while flurries occur every year accumulation isn’t frequent and may not happen for an entire winter. Spring (and specifically May) is the best time to visit, even though nights can be chilly as late as April, and because it’s drier than autumn.