Harpenden pollen forecast - today, tomorrow and the week ahead

Today (9 August) pollen in Harpenden is high; mugwort is high; grass is low. Tomorrow (10 August 2026) levels are similar - mugwort declining. Over the following five days grass and mugwort will increase. Forecasts are calculated by Airmine using satellites to map local vegetation and determine pollen season onset.

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Tree pollen in Harpenden comes mostly from oak and birch, with parks and mature gardens standing in contrast to the more built-up centre. Grass pollen from surrounding Hertfordshire fields is significant through the summer months, carried in by the region's typical south-westerlies. It's a pattern shared by plenty of similarly sized towns nearby, shaped more by geography than anything unusual locally.

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

    19/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    High

    70/100

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):

    None

    0/100

  • Willow (Salicaceae):

    None

    0/100

  • Mugwort (Artemisia):

    Medium

    44/100

Air quality in Harpenden

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Frequently Asked Questions

Is pollen high in Harpenden right now?

On 9 August 2026, overall pollen levels in Harpenden are high. Artemisia is the main contributor to airborne pollen, while grass remain at lower levels

Will pollen levels change in Harpenden tomorrow?

On 10 August 2026, pollen conditions in Harpenden will be different from today, with artemisia continuing to decline

Is pollen expected to decrease in Harpenden this week?

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

Which pollen types are currently active in Harpenden?

On 9 August 2026, Artemisia is the dominant pollen source in Harpenden. grass are also present but at lower levels. willow, hazel, and cypress are not currently active.

When is pollen season in Harpenden?
Locals in Harpenden usually notice oak first, with birch not far behind it. Grass pollen then stretches from May into September, with the worst of it typically landing in June and July. Oak pollen typically runs from April to May, and birch keeps things going from March right through to May. Handy to bear in mind before booking that garden party.
How often is the Harpenden pollen forecast updated?

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

Does pollen in Harpenden 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 Harpenden 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 Harpenden, 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 Kingdom?

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Check pollen in other popular cities:

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Data provided by Airmine — Last update: 10 August 2026 at 02:34 CEST (Data is updated four times daily.)

This page provides the latest public pollen forecast for Harpenden.

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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.