Lorraine Williamson
Spain is heading into one of its worst hay fever seasons in recent years, with experts warning of an earlier and more intense onset of symptoms. A combination of mild winter temperatures, heavy rainfall, and worsening air pollution has triggered a surge in pollen levels across the country.
According to the Spanish Society of Allergology and Clinical Immunology (SEAIC), the spring of 2025 could be “exceptionally intense” for those affected by allergies, especially in southern and central regions. Allergy symptoms may begin as early as April and continue well into summer — and possibly into autumn.
Rainfall drives pollen explosion
Above-average rainfall in February and March has boosted vegetation growth. Trees, grass, and shrubs are blooming more vigorously, releasing large amounts of pollen into the air.
This is especially true in Andalucía and Extremadura, where cities such as Jaén, Seville, Badajoz, and Cáceres are already recording high levels of airborne pollen. In some areas, counts may reach 19,000 pollen grains per cubic metre.
Levels are also rising in central and northern regions—including Madrid, Toledo, Logroño, and Pamplona. SEAIC warns that Castilla-La Mancha, Castilla y León, and parts of the Basque Country are likely to see increased risks for allergy sufferers.
Most allergenic plants in Spain
Not all pollen is equal. Some plants are more allergenic than others:
- Olive trees bloom in May and produce highly allergenic pollen.
- Cypress species, common in parks and gardens, can trigger strong reactions.
- London plane trees, often planted in urban areas, bloom in early spring.
- Birch, particularly in the north, is another major allergen.
- Grasses (gramíneas), widespread throughout Spain, are active for extended periods.
- Poplar trees also contribute to the problem, particularly in riverside areas.
While poison ivy may cause skin irritation, it is rarely found in Spain and is not a significant source of airborne allergens.
Climate change and air pollution increase impact
Scientists point to climate change as a key factor in the rising severity of hay fever. Warmer temperatures and CO₂ levels cause many plants to produce more aggressive pollen. The result: stronger allergic reactions, even among those who previously had only mild symptoms.
Meanwhile, air pollution in cities makes matters worse. Particulate matter and vehicle emissions irritate the nose, eyes, and lungs, making it easier for pollen to enter the body. Together, pollution and pollen create a more hostile environment for people with respiratory conditions.
Could half the population become allergic?
The World Health Organisation estimates that by 2050, half of the global population will suffer from some form of allergy. In Spain, around 20% to 25% of people are already affected. Hay fever remains one of the most common allergic conditions nationwide.
Rain brings relief, wind spreads pollen
While rain encourages plant growth and more pollen in the long run, it can temporarily bring relief. Moisture weighs down pollen grains, helping them settle and reducing exposure.
Dry, windy weather is more dangerous. On such days, pollen remains suspended in the air longer and travels further — especially in open or rural areas.
How to manage hay fever in Spain
Doctors recommend starting antihistamines before symptoms peak. For those with severe or frequent reactions, immunotherapy may offer long-term relief.
Here are a few ways to reduce exposure:
- Check daily pollen forecasts and plan activities accordingly.
- Keep windows closed, especially during peak hours around midday.
- Wear sunglasses and masks on windy days.
- Avoid grassy or wooded areas during high pollen periods.
- Shower and change clothes after spending time outside.
- Dry clothes indoors to prevent pollen from sticking to fabrics.
Identifying which plants trigger your symptoms is key. With the right precautions, it’s possible to manage hay fever — even in what looks set to be a difficult year.
Also read: Sharp increase in asthma and allergies among children in Spain