I have seasonal allergies that are so bad that I’m thinking about escaping them for a bit in late April. I was wondering about tree pollen counts in Tenerife, in particular, birch tree pollen. I’ve read on the internet that grass pollen counts tend to be really low over there, but those do not really bother me. I haven’t been able to find a lot about tree pollen.
For Europe, a good general source of information is PollenInfo.org, hosted by the Medical University of Vienna. The maps and forecasts it provides are very high-level, however (e.g. continent-level maps of birch pollen), and they do not list any preferred provider of local information in Spain.
For local information, weather websites might be a better bet, though not every weather news provider has agreements for every locale in the world for pollen forecasts (as with astronomical data, air quality, ultraviolet exposure, powder or surf conditions, and so forth), and the level of detail varies considerably.
The most detailed pollen information I've found online by far is at Meteovista, a Netherlands-based weather site, which provides tables like this one:
Some of the larger U.S. based sites, like Weather Underground or Weather.com, will at least break down pollen levels by type (tree, grass, and weed), but not all seem to have coverage, for instance my preferred app, WeatherBug.