The orography of Liguria influences considerably the pattern and distribution of rains. Eastern Liguria is affected by sirocco winds that cause bad weather conditions, while Western Liguria is affected by westerlies that allow for more settled weather conditions. In particular, when winds blow from north and north-east, temperatures rise considerably and the rate of humidity lowers. At this stage, the weather in Eastern Liguria is cloudy and rainfall is high, while it is lower in Western Liguria rains. From December to February, the area between Capo Mele and the border with France has lower rainfall than Genoa and slightly higher rainfall than the mountainous area between Chiavari and La Spezia -in this area the rainfall total is sometimes similar to the one registered in North-eastern Italy during the same period of time.
In cases of settled weather conditions, Western Liguria is characterised by Levanters (from East) all along its extent to the border with France. Sirocco winds (from South – South-east) are rare. North-west and west winds are also rare because of the Western Alps. This two phenomena are at the basis of the exceptionally lovely climate of the coastal area between Capo Mele and the border with France. And this is why Western Liguria can enjoy a high number of sunny days – almost as equal as the one in Southern Italy – even during wintertime.
The sea acts as a thermoregulator and thus there are no substantial differences between the minimum temperatures of the two sides of Liguria, though in winter notable differences can be registered between minimum temperatures in seaside resorts – always above zero – and the hinterland – often below zero .
During wintertime, the temperature range is low; the number of sunny hours per day is high; and the rainfall is low. If we compare the rainfall patterns of San Remo with Genoa’s and Cuneo’s (a town in southern Piedmont), we will find considerable differences, though these areas are fairly close to each other.
The mountains act as a barrier that shields Western Liguria from disturbance, thus differentiating the climate in these two bordering areas. San Remo and its surroundings can actually enjoy a fairly milder climate than Genoa. Snow and harsh temperatures are almost exceptional events in San Remo.
As far as rainfall in Liguria is concerned, it is low during summer and rather high during fall, while in Cuneo rainfall is rather high during springtime and it follows a more regular pattern during the rest of the year. Within Liguria, though, there is a clear distinction between Genoa’s and San Remo’s rainfall amounts: as already mentioned, Eastern Liguria is characterised by more precipitation. In the end, the high number of sunny days, the low temperature range, low rainfall, and mild winters are due to several factors, such as the conformation of the coast, the thermoregulatory effect of the sea, and the presence of a natural barrier – i.e., the mountains.