Holidays like Semana Santa (Easter) and Feria de Abril (April Fair) kick off the high season, ushering in inflated rates and crowds. Avoid Seville in July and August when temperatures can reach 100 degrees-plus.
Even in winter, temperatures are mild, rarely dipping below 40 degrees, and occasionally reaching the 70s. The prices during this time are pleasant.
The idea time to visit is on the cusp of entering (or emerging from) winter when the city experiences nearly perfect weather (temperatures average in the high 60s) and minimal crowds.