The northern and central regions of the continent will have, at least until Thursday, high and very high concentrations of pollen in the atmosphere, according to the Portuguese Society of Allergology and Clinical Immunology (SPAIC).

According to the pollen bulletin, released by SPAIC, until June 30, low to moderate levels are expected in the south of the continent.

For the Madeira archipelago low levels of pollen are expected in the atmosphere and high levels in the Azores.

SPAIC adds that throughout the country, pollen grains from grass and parietaria herbs predominate, which have a high allergenic capacity.

In the Lisbon and Setúbal region, pollens are found at moderate levels, with a predominance of grass and parietary herbs, and the eucalyptus tree.

In Porto (Between Douro and Minho region), pollens are at very high levels, especially grass and parietaria herbs and the chestnut tree.

In the region of Trás-os-Montes and Alto Douro, pollens are also very high from grass, parietaria and plantain, and from olive and chestnut trees.

In Coimbra (Beira Litoral region), levels are also very high and there is a predominance of pollen from grass and parietaria grasses.

In the region of Beira Interior (Castelo Branco), pollens with high levels of grass and parietaria herbs and olive, oak and chestnut trees stand out.

In Évora (Alentejo region), pollens are found at moderate levels in the atmosphere, with a predominance of pollens from grass and parietaria grasses.

In the Algarve region, with moderate levels, pollens from grass and parietaria herbs dominate.

According to SPAIC, outdoor activities should be avoided when pollen concentrations are high.