In the air today
20particles per m³ of air
24Thu
27Fri
7Sat
4Sun
20Mon
What kind
- TreesOak, birch, plane and the rest. Peaks March to June.None caught
- GrassMostly May to July, with a tail into the autumn.Low2 per m³
- WeedsRagweed above all, from mid-August until the first frost.Moderate18 per m³
Which plants (Monday, August 24)
- Ragweed56%
- Grass11%
- Nettle11%
- Fern spores11%
- Hops family11%
Share of the grains counted that day, not a separate count for each plant.
Also counted upstate
Armonk, Westchester7 per m³
Wednesday, August 26 · mostly ragweed
Thirty-odd miles north, and usually ahead of the city on tree pollen in spring. Useful as a warning, not as your number.
What this doesn’t tell you
One sampler on one roof in Midtown, collecting over a full 24 hours. It is not a reading for your block and not a reading for right now — wind, rain and the trees on your own street all move it. A low count citywide can still be a bad morning under a plane tree.
Counts are posted by hand during the season and stop for the winter. Nothing here is medical advice.