The pollen bulletin published weekly by SPAIC predicts high pollen concentrations in the air in the regions of Castelo Branco, Coimbra, Évora, Lisbon and Vila Real until 19 June.

Pollen grains in the atmosphere come mainly from olive, cork and oak trees and grasses such as sorrel, plantain, chenopodium, nettle and urticaceae (including pellitory), says SPAIC.

For Porto and Faro, in the Algarve region, the pollen concentration in the atmosphere is expected to be moderate.

Low pollen concentrations in the atmosphere during this period are expected only for Funchal, in the autonomous region of Madeira, and Ponta Delgada, in the autonomous region of the Azores.