Which pollen am I allergic to?
The fastest non-clinical way to narrow this down is timing. Tree, grass and weed pollen peak in different parts of the year, so when you feel bad is a strong clue about what you are reacting to.
The rough calendar
| Season | Usual culprit | Typical window (temperate US) |
|---|---|---|
| Late winter to spring | Tree pollen | roughly February–May |
| Late spring to early summer | Grass pollen | roughly May–July |
| Late summer to autumn | Weed pollen, especially ragweed | roughly August–first frost |
| Damp periods, and autumn leaf litter | Mold spores | varies; wet weather raises it |
Shift these earlier in the south and later further north. A warm year stretches them.
Complications worth knowing
- Some trees flower in autumn. Chinese elm, for instance, releases pollen in late summer and autumn — so "tree pollen in September" is not automatically an error in your app.
- Ragweed is not the only autumn weed. Nettle, lambs quarters, plantain and asters all show up in counts, sometimes above ragweed.
- Mold is not pollen, but it triggers similar symptoms and rises in damp weather, which can look like a confusing off-season flare.
- Rain cuts pollen and raises mold. If wet days make you worse rather than better, mold is worth considering.
A simple method
- Keep a note of your bad days for a few weeks — just a date and a rough 1–5.
- Alongside it, record what was actually in the air those days, by plant.
- Look for the overlap. If your worst days line up with high ragweed and not with high grass, that is a real signal.
This is exactly why Pollenary records a daily history per ZIP code and names the plants: after a few weeks you can look back and see which plant your bad days actually track. History is recorded from the day you install it, whether or not you subscribe, so it is there waiting when you want it.
This is pattern-matching, not diagnosis. Allergy testing with a doctor is the only way to know for certain, and it can find triggers a calendar never will — dust mites, pets, mold species.
Pollen levels are a forecast, not a medical measurement. Pollenary is not a medical device and does not diagnose or treat any condition. Talk to a doctor about your allergies.