Guide
Pollen calendar: which trees pollinate each month
Pollen does not all arrive at once. Each tree species has its own flowering window, so allergy season is a sequence of peaks. This month-by-month calendar covers the main urban trees in Barcelona and Madrid.
Pollen season, month by month
The app's interactive calendar shows a ring for every species and lets you filter by your allergies. This is the urban-tree summary: Open the interactive calendar.
| Month | Trees and pollen in season |
|---|---|
| January | Cypress (winter peak) |
| February | Cypress, elm, poplar and willow |
| March | Plane, cypress, mulberry, birch and alder |
| April | Plane (peak), olive, ash, holm oak, pine and mulberry |
| May | Olive (peak), oak, pine and grasses |
| June | Olive, grasses (peak) and lime |
| July | Grasses, lime and pellitory |
| August | Pellitory |
| September | Pellitory |
| October | Pellitory (end of season) |
| November | Low levels |
| December | Cypress (season begins) |
The major tree allergens
- London plane (March–April): widespread along city streets and a leading cause of pollinosis in Barcelona and Madrid. More about plane tree pollen allergy →
- Cypress family (December–March): brings the season forward into winter and is common in hedges.
- Olive and ash (April–June): major allergens, with olive peaking in May, particularly inland.
- Birch and alder (March–April): highly allergenic, especially in northern areas; alder begins earlier.
And the plants that are not trees
Grasses (May–July) are among the most widespread allergens, while pellitory releases pollen for much of the year in Mediterranean areas. They are not trees, so they appear in the calendar but are not yet mapped.
Try it with your city
Polen-tracker is free, requires no account and works on mobile. Open the map or calendar and filter by the trees that affect you.