While you may think of Spain as a dry land of warm winters and sweltering summers where Brits flock to escape the cold and damp, you might be surprised to consider that Madrid is at the same latitude as New York.
I know first hand that some warm air blows up from Africa, along with a fine, red sand that's deposited on cars and patio furniture. But from what I've experienced, Spain is not some European Mexico where the temperatures are springlike year round.
Actually my 2021 in Spain has probably been one of the first real springs I've ever known, the kind where the temperatures creep creep creep up on little cat feet (apologies to Sandburg), almost unnoticeable throughout March, April and May until one day you say to yourself, I don't need to warm up the bathroom for my shower today. A far cry from the ice-storm-that-destroys-your-tulip-magnolia-today-sun-seared-asphalt-that-melts-your-flip-flops-tomorrow transition we typically experience in the Carolinas.
The allergies are the same. Bring your anti-hist.