The south of Tenerife is usually hotter than the north and is the most popular part of the islands for tourists. Here there are every conceivable activity and a huge selection of hotels, restaurants and bars. Also the beaches in south Tenerife are immaculately kept and are lined with promenades with restaurants, bars and cafes.
North Tenerife is generally a bit cooler and may have more cloud cover, so is perfect if you prefer not to be in the scorching sun. The north of the island has also kept its Canarian character where the old towns of the resorts still survive.