| My wife and I were there a few years ago on a cruise in February and we are going again, hopefully in November. The weather is mild. We didn't get to go to the beaches, but the sightseeing is good and the restaurants are good.
If you are planning on going to one and only one island you might want to consider Funchal. Funchal is a Portuguese island as opposed to the Canary's which are Spanish. As a Portuguese island it caters largely to Brit tourists and retirees. Everyone there speaks English. Also the scenery there is spectacular, the main town is cosmopolitan with lots of restaurants and nightlife.
| but yes, mild, and you may miss the German onslaught as they love the Canaries at Christmas time.
Tenerife - the largest island and most varied in climate. Santa Cruz the largest and main port city, but head inland and up El Tiede, the volcano, I rode my BMW R72 up and into the cone. To the NW, tiny little village, Taganana, a tiny fishing village back then. Las Palmas, touristy, in the south, and maybe where your wife will feel most comfortable?
Gomera - have to ply the waters by the interisland ferries, unless Gomera has an airport now. Semi-tropical rain forest at the passes. Curried goat in the local tavernas.
Lanzarote - desolate, moonscape, but beautiful.
Hierro - don't remember much.
Your mileage may vary