At any given time there is always some sort of fiesta going on in Spain. This guide should point you in the direction of some of the events in this area.
January
February
Fiestas de Carnaval - Águilas
March
Día de la Vieja - Old Lady Day - many places on the Thursday in the middle of lent
April
Semana Santa - Holy Week - everywhere
May
June
Moros y Cristianos - Mojácar - also other places on different dates
July
August
Feria de Almería - Almería city
September
October
November
Feria y Fiestas de los Santos - Albox
December
Medieval Market - Albox