Map from Google - Costa_del_Sol

The Costa del Sol (literally, "Coast of the Sun"), the part of the Spanish southern coast belonging to the province of Malaga, has a Mediterranean climate, with mild and relatively rainy winters, and hot and sunny summers. There are towns like Estepona, San Pedro de Alcántara, Puerto Banús, Marbella, Fuengirola, Mijas, Benalmádena, Torremolinos, Málaga, Velez-Málaga, Torre del Mar, Torrox, Nerja.
The wind blows frequently: not by accident, in the past the Costa del Sol was called Costa del Viento (windy coast). In the cold half of the year, the wind comes along with Atlantic disturbances, while in summer it blows in the form of afternoon sea breeze. In the westernmost part (see Estepona), in summer the Levante, the cool wind from the east, can blow, though less frequently than in the province of Cadiz.
Here are the average temperatures of Marbella.
Average temperatures - Marbella
MarbellaJanFebMarAprMayJunJulAugSepOctNovDec
MarbellaJFMAMJJASOND
Min (°C)67911131719191714108
Max (°C)151618212327292926221816
Min (°F)434548525563666663575046
Max (°F)596164707381848479726461

The rains become gradually less abundant as we proceed from west to east: the average goes from 690 millimetres (27 inches) per year in Estepona, to 585 mm (23 in) in Marbella, to 525 mm (20.5 in) in Málaga, to 450 mm (17.5 in) in Nerja, and follow a Mediterranean pattern, in fact most of them fall from October to March, while in summer it almost never rains.
This is the average rainfall in Marbella.
Average precipitation - Marbella
MarbellaJanFebMarAprMayJunJulAugSepOctNovDecYear
MarbellaJFMAMJJASONDY
Prec. (mm)857560402515251555115100585
Prec.(in)3.332.41.610.60.10.20.62.24.53.923
Days9766520126111065

Winter, from December to February, is mild, and is characterized by sunny periods, alternating with periods of bad weather, with wind and rain. When the sky is clear, at night the temperature can go below 5 °C (41 °F), while during the day it is mild, above 15 °C (59 °F). Very cold days are rare: only in the coldest nights the temperature can go down to freezing, but even in these cases, usually during the day it rises above 10 °C (50 °F). In practice, it never snows or freezes.

Spring, from March to May, is mild and sunny, with rainy days still possible, but not very frequent. Starting in May, and sometimes in April, we begin to see the first hot days, with highs around 30 °C (86 °F).

Summer, from June to mid-September, is hot and sunny. Typically, temperatures hover about 27/28 °C (81/82 °F) in June and September, and about 30 °C (86 °F) in July and August, the weather is hot and muggy, but the sea breeze blows, in short, the typical Mediterranean summer. However, when the wind blows from the interior of Andalusia, the heat can be intense, and the temperature can touch 35/37 °C (95/99 °F), and sometimes 40 °C (104 °F); fortunately in these cases there's a moderate wind and the air becomes dry: better to drink often to avoid dehydration.

Autumn, from mid-September to November, is initially warm, and then becomes gradually milder, while Atlantic fronts become gradually more frequent. In October there are still many warm and sunny days, especially in the first half. In November we are now well into autumn, with a mild climate, but also cloudy and rainy. Sometimes the rains are concentrated in a short time and be strong, particularly in the western part.

The amount of sunshine in Costa del Sol is very good in summer, when clear skies prevail, it is good in spring, when, however, cloudy periods are still possible, while it is decent in autumn and winter, when in addition to sunny periods, cloudy and rainy days occur quite frequently.

Fuengirola

For swimming, the Alboran Sea is never very warm, due to the infiltration of water from the Atlantic, in fact it is still very cool in June, when its temperature is about 20 °C (68 °F), then rises to 22 °C (72 °F) in July and September and 23 °C (73 °F) in August, when it becomes acceptable for swimming.
Here are the average sea temperatures.
Sea temperature - Marbella
MarbellaJanFebMarAprMayJunJulAugSepOctNovDec
MarbellaJFMAMJJASOND
Sea (°C)161515161720222322201817
Sea (°F)615959616368727372686463

When to go

The best time to visit the cities of Costa del Sol, for walks and hikes, corresponds to the months of April, May and October, especially if you plan an excursion in the interior of Andalusia, which in summer is often torrid.
For a beach holiday, the best period is instead the summer, from June to mid-September. In the westernmost part, it's better to bring a sweatshirt for cool and windy evenings, especially in June and September, but for safety, even in July and August.

Back to Andalusia.