Tenerife South is drier and warmer than Tenerife North, taken as a average over a year.
Tenerife North is not by any stretch of the imagination cold and it does not rain all the time, it's just damper than the south especially during the winter months, which in Tenerife are from November to March.
The south of the island is a large area, the pictures you see here are more to the South East of the Island looking down from the mountains above Arafo along the south coast, with Gran Canaria being the other Island that you can see
When you think of South Tenerife you automatically think of Playa De Las Americas and Los Cristianos, these being the main tourist areas on the south of the island.
There is much to see and explore away from these tourist areas, please do not fall into the trap of thinking that it's where the youngsters come to drink the night away and then sleep if of on the beach during the day, Yes, they still do it, but it's confined to a very small area of Playa De Las Americas called 'Veronica's', even this area has been regenerated over the last few years and is not the eye sore that it used to be and at night there is a good Police Presence to make sure that there are no problems.
There are plenty of Rural Hotels (Casa Rurals) on the Island , they can be found in many of the the local towns and villages and offer a good base for exploring, walking or just relaxing.
Remember you are never far from the coast on the Island of Tenerife, and you can get there easily by car or bus.