Current Affairs

Heating: the first systems will be switched on on 15 October, but Milan and other cities are reducing the number of hours

The date on which the heating systems are switched on varies depending on the climate zone in which each municipality is located. In the warmest towns, the radiators will only be switched on from 1 December

by Pietro Menzani

13 October 2026

Aggiungi Il Sole 24 Ore
ai preferiti su Google

4' min read

Translated by AI

Versione italiana

4' min read

Translated by AI

Versione italiana

Although temperatures remain high across much of the peninsula, many local authorities are about to give the go-ahead for heating systems to be switched on. However, from mountain towns to the warmer cities of southern Italia, the dates set for switching on the heating vary considerably. The first date to mark in red on the calendar is 15 October for the coldest areas, whilst in milder climates, heating may only be switched on from 1 December. However, both due to the abnormal temperatures recorded in 2026, and with a view to reducing emissions, some local authorities have adopted by-laws amending the annual operating periods and the daily duration of heating system use.

Climate zones

The date on which the radiators are switched on depends on the zone climate zone to which each municipality belongs. The country has in fact been divided into six zones, from A to F, by Decree 412 of 1993. A subsequent decree, dating from 2013, sets out when heating may be switched on in the various zones and for how many hours a day it may remain on.

The allocation was determined on the basis of degree-days (DD), a measure of how cold a municipality’s climate is during the heating season and, consequently, the extent to which buildings need to be heated. DD are calculated by summing the positive differences between the conventional reference indoor temperature (20 degrees) and the average daily outdoor temperature for each day of the annual heating period.

The first local authorities to switch on the heating

In the final category, F, where municipalities have more than three thousand degree-days, there are no restrictions on the period or times of day, and radiators may remain on throughout the year. This category includes numerous mountain towns such as Cortina d’Ampezzo, Pieve di Cadore, Bormio, Sestriere and Bardonecchia.

Zone E, on the other hand, comprises municipalities with a GG figure of more than 2,100 but not exceeding 3,000. Here, heating systems may remain on from 15 October until 15 April, for a maximum of 14 hours per day. Zone E includes numerous cities in northern Italia, including Milan, Bergamo, Brescia, Turin, Novara, Padua, Venice, Verona, Bolzano, all the provincial capitals of Emilia-Romagna, as well as Campobasso, Potenza and Enna.

The hottest areas

Continuing in chronological order of activation, for Zone D – which comprises municipalities with a degree-day total of more than 1,400 but not exceeding 2,100 – the statutory heating period runs from 1 November to 15 April, for a maximum of 12 hours a day. This zone mainly comprises cities in central Italia, such as Rome, Florence, Ancona and Pescara, but also includes, amongst others, Genoa, Nuoro and Avellino.

Zone C, on the other hand, comprises municipalities with a number of ‘GG’ greater than 900 but not exceeding 1,400. Here, heating systems will remain on from 15 November to 31 March, with a limit of ten hours’ operation per day. Cities such as Naples, Bari, Lecce, Cagliari, Catanzaro, Imperia and Latina are part of Zone C.

Heating will be switched on from 1 December in Zone B, which comprises municipalities with a number of days (GG) greater than 600 and not exceeding 900. The deadline for switching off the heating is 31 March. Heating may remain on for eight hours a day. This group includes municipalities in southern Italia such as Palermo, Catania, Syracuse, Agrigento, Messina and Reggio Calabria.

Finally, Zone A comprises the warmest municipalities, namely those with a degree-day total not exceeding 600, such as Lampedusa, Linosa and Porto Empedocle, all of which are situated in Sicily. In this zone, heating may only be switched on from 1 December until 15 March, for a maximum of six hours a day.

Permitted maximum temperatures

The 2013 decree also regulates the maximum permitted temperatures for heating. With regard to buildings used for industrial, craft and similar activities, the law stipulates that, whilst the winter heating system is in operation, the weighted average air temperature must not exceed 18 degrees. A tolerance of two degrees is allowed. In all other buildings, the maximum limit is 20 degrees, again with a tolerance of two degrees.

The case of Milan

Mayors do, however, have the power to issue by-laws which, where there is a proven need, extend or reduce the annual operating periods and the daily operating hours of heating systems. Mayors may also set limits on the maximum permitted room temperature, both in built-up areas and in individual properties.

The City of Milan, ‘in light of the current temperatures, which are above the seasonal average, and with a view to saving energy and reducing climate-changing emissions and air pollutants’, has issued an order dated 9 October stipulating that, from 15 October to 30 October, outdoor lighting will be permitted for a maximum of eight hours a day, between 5.00 am and 11.00 pm.

From 31 October until the end of the heating season, however, heating systems may remain on for a maximum of 13 hours a day between 5.00 am and 11.00 pm. The period during which heating may be used, as provided for by law, will end on 15 April 2027, ‘unless otherwise specified’.

The mayor’s order issued by the Municipality of Milan also confirms that, for the entire duration of the heating season, the maximum permitted temperature for residential buildings will be 19 degrees, with a tolerance of two degrees – one degree lower than the 20 degrees stipulated by law. For buildings used for industrial, craft and similar activities, however, the limit remains unchanged at 18 degrees (plus a two-degree tolerance).

The situation in Emilia-Romagna

The Emilia-Romagna region has decided to postpone the start of the heating season from 15 October to 1 November. The decision was taken as part of the Regional Integrated Air Quality Plan (PAIR) to reduce emissions and forms part of the measures adopted to offset the postponement of the ban on Euro 5 diesel vehicles.