Pollen and allergies — Trieste
Trieste looks onto the upper Adriatic from the edge of the Karst, wedged between its gulf and the limestone plateau that marks the border with Slovenia. The city is sheltered from the open sea but exposed to the winds that roll down from the highlands: the bora, a strong dry north-easterly, refreshes the air within hours, while the foehn brings clear, milder days. Woodland, Mediterranean scrub and historic olive groves alternate on the hills and karst slopes; cypresses, a familiar sight along this stretch of coast, round out the botanical picture of the province.
Periods and allergens to watch
- Late winter and spring: alder and birch in the karst woodland can open the tree-pollen calendar.
- Spring and summer: grasses in urban meadows and grassy margins, with olive flowering on the hills from May.
- Summer: when the bora blows, peaks drop fast; on still days pollen can pool against the highlands.
- Late summer: mugwort and ragweed along roads, railway lines and uncultivated ground inland.
Trieste uses CAMS through Open-Meteo. Concentrations are modeled, not measured locally by this service, at approximately 11 km resolution. The forecast displays alder, birch, grasses, mugwort, olive and ragweed; it does not automatically cover cypress or parietaria, both present in the karst and urban landscape, or every regional species.
Wind is the deciding factor: with a full bora the city clears within hours and concentrations collapse; with calm or weak southerly airflow pollen can linger in the quarters that back onto the plateau. A walk along the Barcola waterfront or on a karst trail may not match the city-centre value. Treat the model as a guide for the area and check real conditions before spending a long time outdoors.