According to forecasts from the Portuguese Society of Allergology and Clinical Immunology (SPAIC), between Friday and 5 June, concentrations will be high in almost all regions of mainland Portugal, especially pollen grains from olive, pine, birch, cork oak and oak trees and grasses.

In the Trás-os-Montes and Alto Douro region, forecasts indicate a moderate concentration, but of the same plants: olive, pine, birch, cork oak and oak trees and grasses.

In the district of Lisbon, the highest concentrations of pollen are in the capital and in the municipality of Setúbal, for the same trees and herbs.

In Évora (Alentejo region), the concentration of pollen in the atmosphere is high, but with emphasis on grains from olive, pine and cork oak trees and grasses, sorrel, plantain, chenopodium, and nettle.

In the Autonomous Region of Madeira, forecasts indicate low concentrations of pollen in the atmosphere, particularly for cypress, pine, eucalyptus trees and also grasses, plantain, chenopodium, sorrel, nettle and urticaceae (including parietaria).

In the Autonomous Region of the Azores, particularly in Ponta Delgada, the concentration of pollen in the atmosphere will also be low, but particularly for cypress (and/or cryptomeria) and pine trees and grasses, plantain, nettle and urticaceae (including parietaria).