bmi flies into Spain, but it may not be too warm at this time of year - I've holidayed quite a lot in Portugal in Spring, and it can be really hit or miss - and that was a month later!
What about Madiera? It is a lot further south, verging on tropical. Family and friends who went there really enjoyed it. But not sure which star partners fly there - don't think TAP is one, but amn't sure.