There are important local climatic variations, especially with wind exposure and total precipitation, between the city centre, the airport, and the "îles Sanguinaires". The annual average rainfall is at the "Campo dell'Oro" weather station (as per the chart) and at the "Parata": the third-driest place in metropolitan France. The heat and dryness of summer are somewhat tempered by the proximity of the Mediterranean Sea except when the sirocco is blowing. In autumn and spring, heavy rain-storm episodes may occur. Winters are mild and snow is rare. Ajaccio is the French city which holds the record for the number of thunderstorms in the reference period 1971–2000 with an average of 39 thunderstorm days per year.