Earthquake zones in Italy: what seismic zones 1, 2, 3 and 4 mean

Every Italian municipality is classified in a seismic zone (zona sismica), from 1 to 4. The figure is easy to find, but also easy to misread: the zone tells you how hazardous the area is, not how safe the house you are looking at is.

The four zones

The classification dates from a 2003 government order (ordinanza) and, since 2006, has used the peak ground acceleration (PGA) with a 10% probability of being exceeded in 50 years, on rock.

The Regions update the classification with their own decisions, and some use sub-zones, for example 2A and 2B in Lazio, 1a and 2b in Basilicata or 3S in Piedmont. The up-to-date national list is published by the Civil Protection Department (Dipartimento della Protezione Civile): in the version of 31 May 2025 about 800 municipalities are in zone 1, about 2,300 in zone 2, about 3,000 in zone 3 and about 1,700 in zone 4.

Earthquake zones in Italy, region by region

The table counts the municipalities of each region by zone, from the Civil Protection list of 31 May 2025. Where a municipality is split into parts with different zones (Rome, Vejano and Pescorocchiano in Lazio) it is counted in its most hazardous zone.

The pattern follows the Apennines and the south. Calabria and Marche have every municipality in zone 1 or 2, and so do most of Abruzzo, Molise, Umbria and Campania. Sardinia is entirely in zone 4, and most of Piedmont, Lombardy and Trentino-Alto Adige is in zones 3 and 4.

Some well-known places:

• Zone 1: L'Aquila, Messina, Reggio Calabria, Cosenza, Syracuse, Norcia, Sulmona.
• Zone 2: Naples, Palermo, Catania, Perugia, Assisi, Ancona, Salerno, Rimini, Verona, Brescia.
• Zones 2 and 3 in different parts: Rome, where the municipal districts fall into sub-zones 2A, 3A and 3B.
• Zone 3: Milan, Turin, Genoa, Bologna, Florence, Venice, Padua, Trieste, Bari, Pisa, Siena, Lucca.
• Zone 4: Cagliari and the rest of Sardinia, Bolzano, Como, Lecce.

What the zone does not tell you

The zone applies to the whole municipality. Within the same municipality the expected shaking varies from place to place and can be amplified by soft ground, slopes or made ground. Above all, the zone says nothing about the building: a well-designed house in zone 1 can be safer than an old, neglected house in zone 3.

That is why the Italian building code (Norme tecniche per le costruzioni, currently NTC 2018) requires new buildings to be designed for the hazard at the exact location, not just the zone.

The questions to ask, zone by zone

In zones 1 and 2

• What year was the building designed? The updated earthquake standards apply to designs from July 2009; before then, many municipalities were not yet classified or were classified under less strict rules.
• What is the structure made of: reinforced concrete, load-bearing masonry, steel?
• Has seismic improvement or upgrading work been done? Is there a seismic risk classification for the building, for example for work under the sismabonus (the tax incentive for earthquake-proofing)?
• Are there cracks, subsidence or recent structural work that is not documented?

In these zones it is worth having an engineer or a geometra (building surveyor) look at the building before the preliminary contract, especially for old masonry houses or buildings with added storeys.

In zone 3

Strong earthquakes are rare but possible, and many municipalities have only moved into zone 3 in the last twenty years: older buildings were not designed with earthquakes in mind. Ask the design year and the type of structure, and watch out for changes such as removed load-bearing walls or widened openings.

In zone 4

The hazard is low. Questions about the condition of the structure are still useful, as they are part of assessing any house.

How to check your municipality and the exact point

You can find the municipality's zone in the Civil Protection list, and the PGA at any point on INGV's MPS04 seismic hazard map. Our report shows both for the address, with the acceleration value at the point and its uncertainty range, and reminds you that a qualified engineer or surveyor is needed to assess the building.

For the rest of the checks, from the area to the documents, see What to check before buying a house in Italy.

Frequently asked questions

What does seismic zone 3 mean?

Strong earthquakes are possible but rare: the expected ground acceleration is between 0.05 and 0.15 g. About 3,000 Italian municipalities are in zone 3, including Milan, Turin, Florence and Bologna. New buildings must be designed for earthquakes, and for older ones the design year and the type of structure are the questions to ask.

Is zone 4 free of earthquakes?

Zone 4 is the least hazardous: the expected acceleration is below 0.05 g and strong earthquakes are very unlikely. Sardinia is entirely in zone 4, together with large parts of Piedmont, Lombardy and Apulia.

Which parts of Italy are most at risk from earthquakes?

The central and southern Apennines, Calabria, eastern Sicily and parts of Friuli. Zone 1 has about 800 municipalities, most of them in Calabria, Abruzzo and Campania.

Does the zone change the price of a house?

Prices follow the area and the building. In zones 1 and 2 a building that has been made earthquake-safe, with documented work, is easier to sell and to insure, and the sismabonus tax incentive has helped many owners do that work.