Malaga can be ok that time of year. I went to Ronda (Xmas till New Year) and the weather was ok most of the time. But as soon as the sun disappears, temperatures drop significantly and you need warmer clothes. Sierra Nevada is rather risky, IMO. Went to Alpujarras (Órgiva and Trevelez) in April and Orgiva was sunny and mild but Trevelez (1600 m) was freezingly cold with snow above 2000 m. And that was April so january could be even more cold. In Januay, I'd stay south of Malaga if I were you.
Malaga can be ok that time of year. I went to Ronda (Xmas till New Year) and the weather was ok most of the time. But as soon as the sun disappears, temperatures drop significantly and you need warmer clothes. Sierra Nevada is rather risky, IMO. Went to Alpujarras (Órgiva and Trevelez) in April and Orgiva was sunny and mild but Trevelez (1600 m) was freezingly cold with snow above 2000 m. And that was April so january could be even more cold. In Januay, I'd stay south of Malaga if I were you.