Explainer: Why Italian Towns Declare Orange and Red Weather Alerts

It usually arrives the evening before, in a message from a friend or a screenshot of a regional bulletin: domani allerta arancione. Within an hour, parents are checking whether school is closed, commuters are wondering about the train, and someone is moving the car out of the underground garage. Italy's colour-coded alert system is a familiar ritual for residents, but it can be confusing for visitors and for anyone trying to work out how seriously to take it.

The colours are not a weather forecast in the ordinary sense. They describe risk: the chance that forecast rain, wind or snow will cause landslides, flooding or other damage on the ground. Understanding that distinction is the key to reading a bulletin sensibly.

Four colours, one idea: expected impact

Italian civil protection uses four levels, and the word behind them all is criticità — criticality, meaning the expected strain on the ground and on emergency services.

• Green (verde) — no significant hydrogeological or hydraulic phenomena expected. Normal attention is enough.
• Yellow (gialla) — ordinary criticality. Localised, limited events are possible: small landslides, flooded underpasses, rapid rises in minor streams.
• Orange (arancione) — moderate criticality. Widespread and potentially dangerous events are considered possible, with damage to buildings, roads and infrastructure.
• Red (rossa) — high criticality. Extensive and severe events are expected, with a real risk to people and to whole areas.

A heavy thunderstorm over dry, well-drained farmland is not the same as the same storm over a steep valley already saturated by a week of rain. The colour reflects that difference, which is why two towns under the same weather system can sit at different levels on the same day.

What the alert is actually for

Most Italian alerts concern hydrogeological risk — landslides, mudflows and flash floods from small watercourses — and hydraulic risk, the behaviour of large rivers such as the Po, the Arno or the Tevere. Regional bulletins often break the alert down by phenomenon: thunderstorms, strong wind, snowfall, coastal storm surge, and sometimes a separate line for hydraulic risk on major rivers.

Summer heat works differently. The heat warnings issued through the health ministry's system use numbered risk levels rather than colours, so a green hydrogeological alert can coexist with a genuinely dangerous heatwave. Forest fire risk also has its own scale in the regions that publish one. If you see a green alert in July, it says nothing about the temperature.

Yellow days are by far the most common, and they are also the ones most often ignored. That is a mistake. The events that cause most day-to-day damage — a swollen stream cutting a country road, a slope giving way above a provincial highway — usually arrive under a yellow warning, not a red one.

Who decides, and when

Alerts are issued by the regional civil protection centres, working within the national warning system coordinated by the Department of Civil Protection. Each region is divided into alert zones, usually named after river basins or geographical areas, and the bulletin assigns a colour to each zone.

The main bulletin typically appears in the early afternoon and covers the following day, with updates in the morning as conditions develop. That timing matters: it is early enough for mayors to act, and early enough for you to plan.

From the bulletin to your street

The regional colour is only the start. Town halls then decide what to do about it. A mayor may close schools, shut parks and cemeteries, cancel markets and outdoor events, close specific roads and underpasses, or ask people not to use basements and garages. These decisions are local and can differ from one comune to the next, so an orange alert in your province does not automatically mean your child's school will be shut.

An orange day, practically speaking

Orange is the level where ordinary plans deserve a second look. It is not a day to cancel everything, but it is a day to reduce exposure to the places where water and slopes cause trouble.

1. Move the car. Underground and low-lying car parks flood first. If you park in one, shift it the evening before.
2. Check your channels. Look at the regional civil protection site and your comune's website or social accounts for ordinances. Do this in the evening, not at 7am.
3. Rethink the route. Avoid underpasses, riverbanks, cycle paths along canals and secondary roads that cross small bridges. A road you drive every day can be the one that floods.
4. Charge and stock. A power bank, a torch, drinking water and any regular medication in the house cover most short outages.
5. Never walk or drive through standing water. Depth is impossible to judge and manhole covers lift. Twenty centimetres of moving water is enough to take an adult off their feet.

Red: when the town slows down

Red alerts are rare, and they are treated as an emergency. Expect schools to close, public transport to be reduced or suspended on exposed sections, some rail lines to run at reduced speed or stop altogether, and civil protection volunteers to be out in the squares and underpasses before anything happens.

The hardest part of a red day is that the sky often looks ordinary. Alerts cover a 24-hour window, and the worst of the weather may arrive at three in the morning or late in the afternoon. If your comune has issued an order, follow it even if the street outside is calm and dry. The order is based on the whole zone and the whole day, not on your window.

Three things people get wrong

The colour is not a rain forecast

An orange alert does not promise a dramatic storm over your roof. It says that conditions exist in which significant damage is possible. Sometimes the forecast shifts and nothing much happens. That is not a failure of the system; it is how probability works.

Your zone is not your neighbour's zone

Alert zones follow geography, not administrative convenience. Two towns twenty kilometres apart can be in different zones with different colours. Check the zone, not the province name.

Green does not mean a pleasant day

Green covers hydrogeological and hydraulic risk. It says nothing about wind chill, summer heat, air quality or sea conditions. Read the whole bulletin, not just the colour square.

A simple routine for alert days

Find your region's civil protection bulletin and bookmark it, along with your comune's official channel. Look at both the evening before anything significant is forecast. If the colour is yellow or above, charge your phone, move the car off low ground, and have a second route in mind for the morning. If it is orange, add a check on schools and offices before you go to bed. If it is red, treat the day as one where staying put is the sensible default.

One more thing worth doing in a quiet week rather than a wet one: look at your comune's civil protection plan, which sets out which streets and neighbourhoods are most exposed. Knowing in advance which underpass floods and which stream rises fast turns an alarming message into a manageable one. And if a property, a business or a family member's health is affected by flooding or extreme heat, take advice from a qualified professional rather than relying on a weather alert to make the decision for you.

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