An alternative to Mallorca- Granada Andalusia?

Lanzarote is  good option especially with the weather. Plenty of riding and hire shops. Tabayesco and Mirador del Rio in the North and Femes in the South are testimg climbs and there is a lot of undulating, flat riding to be had. Its windy though and the landscape is not to everyones taste. Girona obviously but look at the southern end of the Tramuntana mountains in Mallorca. I much prefer the riding around Es Capdella and Puigpunyent and you can get to the flatter east side, Palma and you still have the MA10 up to Valdemossa. Use Mallorca Cycle Shuttle to get you over to the east coast and ride back or vice versa.  You really can't beat Mallorca on many levels 

Just a word of warning: both Ronda and Granada can get a little bit chilly in March (specially in March) or April... be sure to take a look at an average temperature chart before deciding.

As HLaB already stated, the Costa Blancla (Calpe, Benidorm...) area seems to be the most popular cycling destination in mainland Spain during this part of the year. There are a handful of pro teams that host their winter training camps in the area, there are several cycling hire shops and no lack of routes to try (Tudons bing perhaps the obvious highlight).

If I have to point out something bad from the area, that would the heavy traffic on the coastal road that links all the touristic destinations in the Costa Blanca area. I've been there a couple of times (during a family summer vacation, never cycling) and I admit I thought that cycling in the coastal road didn't look safe.

Betera, inland from Valencia, is a good option. Lots of great riding round there, including many climbs, but also some easier options for a rest or recovery day. Not expensive and the locals (most of whom seemed to ride) are very welcoming. Good coffee and cake options dotted around and decent grub in the evenings.

Ronda makes for a good cycling base. It's about 45 minutes inland from Malaga and is a lovely little town with plenty of accomodation options and good restaurants.

There is a good cycle hire shop (cycleronda) and the owner has good information and maps with local cycling routes. It's generally a very hilly area, but there are options to the east and west which offer a more leisurely circuit.

There are plenty of little villages scattered around, with cafe stops.

A couple of good rides are: heading North West for a loop around Zahara lake or North East towards El Chorro/Teba.

I've been three times now, always in the winter months between November and March. We had one day of rain. I'll be heading back to the area in January.

Another good option is Girona, the weather should be fine in March/April. You can find some challenging rides (heading east up to Susqueda Dam) or head west over 'Els Angels' and drop down toward the coast. Again, there are loads of little towns with cafes/restaurants.

I found that there were plenty of varied routes for the week we spent there.

Costa Blanca, Denia/Murcia area perhaps?

We are going for a family trip to Alora, north of Malaga at 1/2 term. Plenty of interesting looking roads between the mountains and the coast.  The A7000 road north out of Malaga has two spirals on it that would be on anyone's list.