Rome Geography, Climate & Nature

Rome sits on the Tiber about 25 kilometres from the Tyrrhenian Sea, in a volcanic landscape that shaped everything the city was built from.

The hills

The famous seven — Palatine, Capitoline, Aventine, Caelian, Esquiline, Viminal and Quirinal — are low spurs of volcanic tuff rising perhaps forty or fifty metres above the river plain, separated by valleys that were marshy before they were drained. They are less dramatic than the phrase suggests, but they were defensible and above the flood line, which is the whole reason the city is here.

The Tiber

Navigable from the sea to this point and fordable at the Tiber Island, which made this the meeting of a river route and a coastal road. The river flooded catastrophically and repeatedly until the high embankment walls were built in the 1870s, which ended the floods and also cut the city off from its river.

Volcanic rock

The Alban Hills to the south-east are a volcanic complex, and their products built Rome: tuff for blocks, travertine from Tivoli for facing, and above all pozzolana, volcanic ash that reacts with lime to make a concrete that sets underwater and is still standing after two thousand years.

Water

Springs in the surrounding hills fed eleven aqueducts, several of which still deliver water to the fountains today.

Twenty metres down

The modern street level sits several metres above the ancient one across much of the centre — the accumulated debris of collapse, flood silt and rebuilding. It is why the Pantheon is approached down steps that were once up them, why the Forum lay buried as a cow pasture until the nineteenth century, and why every excavation for a metro line turns into an archaeological dig that adds years to the schedule.

The campagna

The rolling country around the city, malarial until the twentieth century and now largely suburb.

Rome has a Mediterranean climate, with a genuinely hot summer and a winter that is mild rather than cold.

Summer

June to August is hot and dry: highs of 30 to 34°C, frequently higher, with very little rain and strong sun. The stone and asphalt hold heat, so the city is several degrees warmer than the surrounding countryside and stays warm into the night. Romans leave in August, and many small restaurants and shops close for two or three weeks around Ferragosto on the 15th.

Winter

December to February is mild and damp: 12 to 14°C by day, 3 to 5°C at night, with most of the year’s rain falling as heavy showers rather than persistent drizzle. Snow is rare enough that a few centimetres shuts the city.

Spring and autumn

April, May, September and October are the best months by a wide margin — warm days, cool evenings, and light that makes the stone look the way it does in paintings.

Rain

Around 800 millimetres a year, more than London, concentrated between October and December.

The wind

Two winds matter. The tramontana comes cold and dry off the Apennines in winter and produces the brilliantly clear days when the mountains are visible from the Janiculum. The scirocco arrives from the Sahara at any season, warm, heavy and sometimes carrying reddish dust that films the cars, and Romans blame it for headaches and bad temper.

Practical effect

In summer, do the archaeology at opening time, take the middle of the day indoors or over a long lunch, and come out again after five. The Forum and Colosseum have almost no shade.

Rome has one of the largest areas of green space of any European capital, and the reason is aristocratic rather than ecological: the city is ringed and threaded with the parks of villas laid out by the Italian nobility. Most were destroyed in the building boom of the late nineteenth century, but the survivors are large — Villa Doria Pamphili runs to about 1.8 square kilometres west of the Janiculum, and Villa Borghese and Villa Ada are the other two of the notable three. The comune covers roughly 1,285 square kilometres in total, much of it green.

The serious habitat is outside the centre. The Appian Way Regional Park protects around 4,580 hectares and is the second-largest urban park in Europe, established by the Region of Lazio as a “green wedge” driven between the city centre and the Alban Hills. Inside it, the Parco degli Acquedotti covers about 240 hectares and is named for the aqueducts that cut across it — the Aqua Felix and the Aqua Claudia — while the Caffarella valley runs from the Aurelian Wall out to the Almone. It also holds most of the ancient Roman remains that survive outside the historic centre, which makes it the one place in Rome where archaeology and open country are the same walk.

Two genuine nature reserves sit at the city's edges, at Marcigliana to the north and the Tenuta di Castelporziano on the coast, and there is a substantial pine wood at Castelfusano near Ostia. More recent regional parks include the Pineto. In Trastevere, the Orto Botanico is the shaded formal counterpart to all of that.

The water is the connecting thread. The Tiber is the third-longest river in Italy and the longest in central Italy, rising at Mount Fumaiolo and reaching the sea at Ostia; the Aniene joins it north of the historic centre. The city's ground rises from 13 metres above sea level at the base of the Pantheon to 139 metres at the top of Monte Mario — a range small enough to walk and large enough to explain where the villas were built.

Rome's most conspicuous wild animal is a parrot. Rose-ringed parakeets have colonised the city, and the places to see and hear them are specific: the gardens of the Palatine Hill, the trees of Trastevere and the Janiculum, and Villa Borghese. They are a naturalised population descended from escapes and releases, part of a late-twentieth-century spread that has taken the species further north than any other parrot breeds, and once you have registered the call you will not stop hearing it over the centre.

The introduction is not harmless, and the honest version is worth having. Where these birds have become abundant elsewhere they have displaced other cavity-nesting species — in one documented case in Seville, a greater noctule bat population fell sharply as the parakeets increased twentyfold, with the parakeets attacking the bats directly. A flock of bright green birds over a Roman pine is a pleasure and an introduction at the same time.

The other animal Rome is known for is the cat, and it has an address. The Torre Argentina Cat Sanctuary occupies Temple D at Largo di Torre Argentina, among four Roman Republican temples sunk below the modern street. It was founded in 1993, runs as a no-kill shelter with sterilisation and adoption programmes, and houses an estimated 350 cats. Visiting is free and the volunteers will talk to you; it is also the easiest way in Rome to look closely at Republican-era temple podia.

For anything beyond the naturalised and the feral, go out rather than in. The reserves at Marcigliana and the Tenuta di Castelporziano, the Castelfusano pine wood and the Caffarella valley inside the Appian Way Regional Park are where Roman countryside species still have room, and the two hours it takes to reach them is the price of seeing any of it.