The weather during January consists of many sunny days with little, or no, cloud. The sea has cooled considerably and the heavy showers caused by the warmer seas of early winter are less prevalent. With the sun at it’s weakest, relatively speaking, there is less chance, than at any time of year, of showers developing over the land.
Of course, it does rain sometimes. Occasionally an active cold front moves across Spain from the Atlantic and maintains sufficient moisture after it’s passage across Iberia to give a few hours of steady rain along the Costa Del Sol. Once the front has moved away into the Mediterranean, a stiff northwest wind often develops, a chilly wind, but with sparkling visibility and little, or no cloud. An afternoon with this northwesterly breeze may be accompanied by temperatures of 17 Celsius (63F) or more, but the low relative humidity, sometimes down to 15%, or less, certainly makes it feel cold in the shade. At night, temperatures fall quickly, and even with the wind persisting, temperatures may drop below 5 Celsius (41F). Occasionally, if the wind falls calm, values in more rural areas may drop close to, or even a shade below, freezing.
Sometimes, but fortunately very rarely, low pressure settles in the western Mediterranean, and weather fronts move from the east bringing spells of quite heavy rain, perhaps with thunder. These unsettled spells can often last for several days, and although welcomed by the skiers on the mountains above Granada, they can prove fairly depressing for holiday makers. Weather like this may produce 50 mm (2 inches ) of rain in quite a short space time.
Despite these mentions of bad weather, conditions are generally good. The emphasis is very much on plenty of sunshine, afternoon temperatures near 16 Celsius(61F) and mostly light winds. In the sunshine, and on the patios, the more hardy among us can wear T-shirts and shorts, but for an evening stroll a fleece or jacket is recommended. Those rising at the crack of dawn, not a common event, given the late eating hours in Spain, temperatures are usually just below 10 Celsius (50F) and a warm sweater or jacket is required