St. Charles pollen forecast - today, tomorrow and the week ahead

Today (16 July) pollen in St. Charles is low; grass is low. Tomorrow (17 July 2026) levels are similar. Over the following five days grass will increase. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.

For long term forecasts and maps, see the Airmine app

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

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St. Charles's Missouri River setting features oak, hickory, and cottonwood as the main tree pollen sources, with exposure varying between the wooded residential neighborhoods on the upland bluffs and the more built-up historic Main Street and river bottom commercial areas. The Missouri River floodplain corridor is particularly significant for cottonwood pollen, while the bluff-to-river elevation gradient creates distinct local pollen zones.

Today - 16 July

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    Low

    21/100

  • Oak (Quercus):

    None

    0/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    None

    0/100

  • Ragweed (Ambrosia):

    None

    0/100

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 - 17 July

  • Alder (Alnus):

    None

    0/100

  • Birch (Betula):

    None

    0/100

  • Hazel (Corylus):

    None

    0/100

  • Cypress (Cupressaceae):

    None

    0/100

  • Grass (Poaceae):

    Low

    9/100

  • Oak (Quercus):

    None

    0/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    None

    0/100

  • Ragweed (Ambrosia):

    None

    0/100

Air quality in St. Charles

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Frequently Asked Questions

Is pollen high in St. Charles right now?

On 16 July 2026, overall pollen levels in St. Charles are low. Grass is the main contributor to airborne pollen

Will pollen levels change in St. Charles tomorrow?

On 17 July 2026, pollen conditions in St. Charles will be similar to today, with grass at low levels

Is pollen expected to decrease in St. Charles this week?

According to the five-day outlook, grass and ambrosia pollen levels will increase later in the week.

Which pollen types are currently active in St. Charles?

On 16 July 2026, Grass is the dominant pollen source in St. Charles. oak, willow, alder, ambrosia, artemisia, birch, and cypress are not currently active.

When is pollen season in St. Charles?
St. Charles's St. Louis suburban Missouri setting produces a season opening in late February with elm and maple before oak peaks through April. Grass from surrounding Missouri and Illinois farmland peaks through June and July before mugwort and nettle extend exposure into September. The Missouri River valley channels airflows, while the continental climate produces a well-defined seasonal progression throughout.
How often is the St. Charles pollen forecast updated?

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

Does pollen in St. Charles 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 St. Charles 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 St. Charles, 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.

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Data provided by Airmine — Last update: 16 July 2026 at 05:36 CEST (Data is updated four times daily.)

This page provides the latest public pollen forecast for St. Charles.

For long term forecasts and maps, see the Airmine app

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