The Bronx pollen forecast — Castle Hill neighborhood
Pollen Today
Today (20 September) pollen in Castle Hill, The Bronx is moderate; grass and ragweed are moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) levels are similar to today.
7-Day Trend
Over the next week mugwort will increase; grass and ragweed will decrease.
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Pollen Risk
Today - 20 September
| Pollen species | Level | Value |
|---|---|---|
| Alder (Alnus) | None | 0/100 |
| Birch (Betula) | None | 0/100 |
| Hazel (Corylus) | None | 0/100 |
| Cypress (Cupressaceae) | None | 0/100 |
| Grass (Poaceae) | Moderate | 35/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 46/100 |
Tomorrow - 21 September
| Pollen species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alder (Alnus) | None | 0/100 | — |
| Birch (Betula) | None | 0/100 | — |
| Hazel (Corylus) | None | 0/100 | — |
| Cypress (Cupressaceae) | None | 0/100 | — |
| Grass (Poaceae) | Moderate | 34/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Moderate | 44/100 |
Local Environmental Conditions
A waterway supports hazel and willow along its bank, both strongly allergenic wind-pollinated species, just outside the immediate area. This area, close to home here, has a mix of oak and birch trees, birch in particular a notorious spring allergen source. A green space where lawn grass and ornamental plantings top up the local grass and ragweed count; this sits within the local area.
The waterside hazel and willow are consistently first to release pollen each year, hitting its peak before most trees have even budded, around late winter into March. Oak and birch in the nearby woodland follow in mid-to-late spring, usually peaking from April into May. Through late spring, grass pollen climbs steadily toward its June peak, handing off to ragweed, which peaks from mid-August through October.
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Frequently Asked Questions About Pollen in New York
Is pollen high in The Bronx right now?
On 20 September 2026, overall pollen levels in The Bronx are moderate. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in The Bronx tomorrow?
On 21 September 2026, pollen conditions in The Bronx will be similar to today, with ambrosia at moderate levels, grass at moderate levels
Is pollen expected to decrease in The Bronx this week?
According to the five-day outlook, ambrosia and grass pollen levels are expected to gradually decrease, while artemisia pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in The Bronx?
On 20 September 2026, Ambrosia is the dominant pollen source in The Bronx. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in The Bronx?
How often is the The Bronx pollen forecast updated?
The The Bronx pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in The Bronx come from nearby or far away?
Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.
Are pollen levels in The Bronx based on measurements or forecasts?
Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.
Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in The Bronx, modern forecasts combine recent measurements, weather data, and information about local vegetation.
This allows us to estimate pollen levels for today and the coming days, not just report the past.
Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.
Understanding the Scale
The 0–100 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
Pollen
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
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Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
