Spain is a relatively large country and as such it experiences different weather conditions in different regions, but for the most part it has a sub-tropical climate. There is a natural divide in the middle of the country with the Cantabrian Mountains. The regions north of the mountains have rainier weather and those south are much drier.

The rainier areas include the Basque country, Asturias, Galicias and Cantabria. This is a much more temperate climate and there are only slight variations in temperature throughout the year. Both summer and winter are very mild. The regions along the Atlantic coastline have fairly high rainfall and temperatures are mild all year round, with an average of 9°C in the winter and up to 18°C during the summer months. Annual rainfall can be anything between 800 and 1500 mm. The summer months will see a reasonable amount of dry weather.

The drier areas often have scorching temperatures, although there is always the possibility of a sudden thunderstorm. This region does vary a little more in its weather though. The inland areas have the hot summers but winters see the temperatures fall fairly low. Frost and snow are not uncommon in these areas and temperatures have been known to drop as low as -15°C. The annual rainfall in these areas is usually below 400mm. The Mediterranean coastline has mild temperatures all year round with averages in winter at 11°C and the average in summer at 23°C.

The city of Barcelona has warm temperatures all year round but has a rainy season from September to October. The average temperature in winter there is around 9°C and in summer it is 24°C. Madrid has much more unpredictable weather as it is further north. The average winter temperature in Madrid is 6°C and in summer it is 25°C. In Alicante the average temperature during the winter is around 12°C and in summer it is 26°C. In the city of Bilbao the average winter temperature is 9°C and in the summer it is 22°C. On the island of Ibiza the average temperature in winter is 12°C and in summer it is 26°C. In Malaga the average winter temperature is 12°C and in summer it is 25°C. Average temperatures in Seville in winter are 10°C and in summer they can be as high as 28°C.

Spain is one of the sunniest countries in Europe and the number of hours of sunshine each year varies from 1700 in the northern regions to more than 3000 in southern regions and the Canary Islands.

Rainfall varies in different areas of Spain. The desert area around Almeria receives less than 150mm each year, while cities such as Bilbao have high levels of rainfall at an average of 2400mm each year.

Humidity levels can be fairly high in some areas. They are around 70% all year round in Barcelona and in Madrid levels fluctuate between 50 and 80%.

As with most European countries there are four distinct seasons to the year. Summer runs from June to August and sees the best of the weather. Autumn is from September to November and is a warm season although milder than the summer. Most areas will only see temperatures drop significantly towards the end of the season. Winter runs from December to February and there are parts of Spain, such as the Canary Islands, which have temperatures in the mid 20s at this time of year. Spring is from March to May and there is an average of 11 hours of sunshine each day in some areas and towards the end of the season, temperatures are on a par with those in summer.

Unless you are in one of the mountain regions or are inland during the winter months, you should not need anything other than light clothing while in Spain. Evenings can be considerably cooler, so a light jacket or sweater might be needed.

The country does see the occasional hurricane and there are plenty of storms in some regions. The country has as many as 2500 earthquakes each year although many of these are so mild that they cannot be felt. There are a number that do cause damage to property and life and the most recent of these was in May 2011 in the town of Lorca, which claimed several lives.