Greencastle pollen forecast - today, tomorrow and the week ahead

Today (9 August) pollen in Greencastle is medium; ragweed is medium; grass is low. Tomorrow (10 August 2026) levels are similar - grass remains low, ragweed remains medium, mugwort at low levels. Over the following five days grass, mugwort, and ragweed will decrease. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.

Get the full experience in the Airmine app.

Download on the App Store Get it on Google Play

Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

Follow your pollen exposure and performance with the free Airmine–Strava integration. See your pollen and air quality exposure for every Strava activity.

Learn more

Set on rolling farmland in west-central Indiana, Greencastle's landscape is defined by oak-hickory forest alongside sugar maple and farmland crops, the main contributors to seasonal pollen exposure. Exposure varies with proximity to green space versus the more built-up parts of Greencastle. The mix of native and introduced species here is fairly typical for this part of the country.

Today - 9 August

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    Low

    2/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    None

    0/100

  • Ragweed (Ambrosia):

    Medium

    30/100

High pollen levels may trigger sneezing, itchy eyes, and congestion. Airmine's neighbourhood estimates use satellites to map local vegetation and a statistical prediction model, updated four times daily.

Tomorrow - 10 August

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    Low

    16/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    Low

    14/100

  • Ragweed (Ambrosia):

    Medium

    46/100

Air quality in Greencastle

View air quality

Frequently Asked Questions

Is pollen high in Greencastle right now?

On 9 August 2026, overall pollen levels in Greencastle are moderate. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels

Will pollen levels change in Greencastle tomorrow?

On 10 August 2026, pollen conditions in Greencastle will be different from today, with ambrosia at medium levels, artemisia at low levels, grass at low levels

Is pollen expected to decrease in Greencastle this week?

According to the five-day outlook, ambrosia, artemisia, and grass pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.

Which pollen types are currently active in Greencastle?

On 9 August 2026, Ambrosia is the dominant pollen source in Greencastle. grass are also present but at lower levels. artemisia and cypress are not currently active.

When is pollen season in Greencastle?
Pollen season in Greencastle starts with maple and elm in March before oak extends the tree season through April. A grass pollen peak follows through May and June; ragweed extends the season into September. The continental Midwest climate produces a well-defined spring tree peak followed by a strong late-summer ragweed season, a defining feature of the local season.
How often is the Greencastle pollen forecast updated?

The Greencastle pollen forecast is updated four times daily. See the timestamp below for the most recent update.

Does pollen in Greencastle 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 Greencastle 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 Greencastle, 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.

Want to see pollen forecasts for other cities in United States?

Atlanta Boston Chicago Dallas Houston Los Angeles Miami New York Philadelphia

Check pollen in other popular cities:

Melton Rio de Janeiro Copenhagen Athens Denpasar Rome Cape Town Barcelona London Los Angeles New York

Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)

This page provides the latest public pollen forecast for Greencastle.

Get the full experience in the Airmine app.

Download on the App Store Get it on Google Play

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.

Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.