Name: Pollen forecast for Harrow (2026-09-01)
Creator: Pollen Count
Published: 2026-09-01T15:30:32Z
License: https://pollencount.org/terms/

🌿

About Pollen in Harrow

Harrow’s allergy profile sees dominant spring Birch and Oak pollen (March-May), sourced from extensive woodlands at Bentley Priory Nature Reserve and Harrow Weald Common; followed by peak summer Grass pollen (June-August) from local playing fields and River Pinn’s marginal meadows.

Topography, including Harrow Hill’s elevation and sheltered suburban parks, can localise and intensify pollen concentrations; late-season mould spores (Sept-Nov) elevate from damp leaf decomposition in parklands and shaded urban areas.

The pollen count in Harrow today is HIGH, driven mainly by Mugwort.

HIGH

15 active species

Refreshing live forecast…

.forecast-refresh-status{display:none!important}.date-tab{cursor:default;opacity:.55}Showing today's cached forecast. Enable JavaScript to switch days and load live data.

4-Day Forecast:

Morning

Grass MED

Tree LOW

Weed HIGH

Afternoon

Grass MED

Tree LOW

Weed HIGH

Evening

Grass MED

Tree LOW

Weed V.HI

Species	Level	Count
🌿 Mugwort	HIGH	29 grains/m³
🌿 Giant Ragweed	HIGH	24 grains/m³
🌿 Common Ragweed	HIGH	21 grains/m³
🌿 Sagebrush	HIGH	18 grains/m³
🌾 Grass (mixed)	MED	12 grains/m³
+35 more tracked Perennial Ryegrass Timothy Grass Cock's-foot Stinging Nettle Russian Thistle Pigweed Fat Hen Ribwort Plantain Western Ragweed Common Sorrel Box Elder Alder Paper Birch Silver Birch Downy Birch Australian Pine Japanese Cypress Hazel Japanese Cedar Mediterranean Cypress Bermuda Grass Ash Mountain Cedar White Mulberry Olive Pellitory-of-the-wall Upright Pellitory Parthenium Weed London Plane Black Poplar Mesquite White Oak Holm Oak English Oak Field Elm All species in the app: Android iOS
🌿 Mugwort	V.HI	42 grains/m³
🌿 Giant Ragweed	V.HI	34 grains/m³
🌿 Common Ragweed	HIGH	29 grains/m³
🌿 Sagebrush	HIGH	26 grains/m³
🌾 Perennial Ryegrass	MED	14 grains/m³
+35 more tracked Grass (mixed) Cock's-foot Timothy Grass Stinging Nettle Russian Thistle Pigweed Fat Hen Western Ragweed Ribwort Plantain Common Sorrel Box Elder Alder Paper Birch Silver Birch Downy Birch Australian Pine Japanese Cypress Hazel Japanese Cedar Mediterranean Cypress Bermuda Grass Ash Mountain Cedar White Mulberry Olive Pellitory-of-the-wall Upright Pellitory Parthenium Weed London Plane Black Poplar Mesquite White Oak Holm Oak English Oak Field Elm All species in the app: Android iOS
🌿 Mugwort	V.HI	38 grains/m³
🌿 Giant Ragweed	V.HI	31 grains/m³
🌿 Common Ragweed	HIGH	26 grains/m³
🌿 Sagebrush	HIGH	23 grains/m³
🌿 Stinging Nettle	MED	10 grains/m³
+35 more tracked Grass (mixed) Russian Thistle Pigweed Fat Hen Cock's-foot Perennial Ryegrass Timothy Grass Western Ragweed Ribwort Plantain Common Sorrel Box Elder Alder Paper Birch Silver Birch Downy Birch Australian Pine Japanese Cypress Hazel Japanese Cedar Mediterranean Cypress Bermuda Grass Ash Mountain Cedar White Mulberry Olive Pellitory-of-the-wall Upright Pellitory Parthenium Weed London Plane Black Poplar Mesquite White Oak Holm Oak English Oak Field Elm All species in the app: Android iOS
🌿 Mugwort	V.HI	34 grains/m³
🌿 Giant Ragweed	HIGH	28 grains/m³
🌿 Common Ragweed	HIGH	24 grains/m³
🌿 Sagebrush	HIGH	21 grains/m³
🌿 Stinging Nettle	MED	9 grains/m³
+35 more tracked Cock's-foot Perennial Ryegrass Timothy Grass Grass (mixed) Russian Thistle Pigweed Fat Hen Western Ragweed Ribwort Plantain Common Sorrel Box Elder Alder Paper Birch Silver Birch Downy Birch Australian Pine Japanese Cypress Hazel Japanese Cedar Mediterranean Cypress Bermuda Grass Ash Mountain Cedar White Mulberry Olive Pellitory-of-the-wall Upright Pellitory Parthenium Weed London Plane Black Poplar Mesquite White Oak Holm Oak English Oak Field Elm All species in the app: Android iOS

Last updated: 15:30 UTC

4-Day Forecast	Tree	Grass	Weed
Tue 1 Sep	LOW	MED	HIGH
Wed 2 Sep	LOW	MED	V.HI
Thu 3 Sep	LOW	MED	V.HI
Fri 4 Sep	LOW	MED	V.HI

Map of Harrow (51.633972°, -0.304218°)

More in United Kingdom

Aberdeen Ashford Aylesbury Banbury Barking and Dagenham Barnet

What Pollen Levels Mean

LOW Symptoms are unlikely

MED Moderate risk of symptoms

HIGH Widespread symptoms likely

V.HI Expect significant symptoms

X.HI Extremely high symptom likelihood & severity