With the arrival of the cold season, the issue of automatically turning on the heating reopens: like every year, the radiators will be activated unevenly throughout Italy, but it will vary based on the climate of each region.
It starts on 15 October 2025 with most of the cities in Northern Italy, and then gradually continues along the country until 1 December 2025. The current legislation in fact provides for the division of Italy into 6 different climate zones, depending on the average seasonal temperatures: in practice, this translates into a difference between the Municipalities regarding the period of heating operation and the daily duration. The shutdown, however, will take place between March 15th and April 15th.
No changes to the legislation are foreseen for 2025, although the Municipalities have the right to impose more restrictive criteria to limit consumption: the Municipality of Milan, for example, has established that the maximum temperature allowed in residential buildings must be 19 °C (with 2 °C tolerance), i.e. one degree less than the 20 °C envisaged by the Decree.
What are the climate zones for turning on heating and how are they calculated
The switching on of central heating is regulated by Presidential Decree no. 74 of 16 April 2013, which establishes switching on and off dates, maximum number of daily hours of operation and maximum temperatures allowed.
The Decree, in particular, divides Italy into 6 different climate zones, depending on the average temperatures of the cold season: these climate zones are determined using the so-called degree-days (often abbreviated as DD or gr-g). This is the positive difference between the temperature of the internal environment (set by legislation at 20°C, with a 2°C tolerance) and the average daily external temperature. The data is collected every day of the year: the higher this value, the harsher the climate in that area and, consequently, the sooner the heating can be turned on.
| Climate zone | Degree-Days |
|---|---|
| Zone A | less than 600 |
| Zone B | between 600 and 900 |
| Zone C | between 901 and 1400 |
| Zone D | between 1401 and 2100 |
| Zone E | between 2101 and 3000 |
| Zone F | above 3000 |
The 2025 calendar for turning on heating in Italy
A different switch-on period and a variable number of hours of daily operation are therefore established for each climate zone. Specifically, the subdivision ranges from a maximum of 14 hours per day for zone E to a maximum of 6 hours for zone A.
| Climate zone | Ignition period | Operating hours |
|---|---|---|
| Zone A | 1 December – 15 March | 6 hours per day |
| Zone B | 1 December – 31 March | 8 hours per day |
| Zone C | 15 November – 31 March | 10 hours per day |
| Zone D | 1 November – 15 April | 12 hours per day |
| Zone E | 15 October – 15 April | 14 hours per day |
| Zone F | all year round | no limitations |
While zone A is the smallest and includes only Lampedusa, Linosa, Porto Empedocle, zone E is actually the most populous, with around 4,000 municipalities involved and almost all the cities of the North. Zone F includes only Belluno and Cuneo; that B, however, includes all the provinces of Sicily together with Crotone and Reggio Calabria. Lastly, most of the municipalities in Central Italy are located in the CD area.
For 2025, no changes have been made to the legislation: however, Italian municipalities can still choose to apply more restrictive criteria for the use of heating, so as to allow greater energy savings. In the case of Milan, mayor Beppe Sala confirmed that the maximum temperature inside buildings must be 19°C, always with a 2°C tolerance, i.e. one degree less than the 20°C established in the Decree.
