Name: Pollen forecast for Hillingdon (2026-09-01)
Creator: Pollen Count
Published: 2026-09-01T15:30:33Z
License: https://pollencount.org/terms/

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About Pollen in Hillingdon

Hillingdon’s spring allergy profile is dominated by Birch (March-April) from mature park trees like those in Ruislip Woods; Oak pollen follows (April-May) across borough green spaces. Summer features ubiquitous Grass pollen (May-July), originating from extensive local meadows, sports fields, and the River Colne/Grand Union Canal banks.

The borough’s urban-fringe geography and sheltered residential areas can locally elevate pollen concentrations; dry, windy conditions enhance airborne dispersal. Autumn-winter sees Mould spore prevalence, linked to damp leaf litter and decomposing vegetation in wooded areas.

The pollen count in Hillingdon today is HIGH, driven mainly by Giant Ragweed.

HIGH

15 active species

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4-Day Forecast:

Morning

Grass MED

Tree LOW

Weed MED

Afternoon

Grass MED

Tree LOW

Weed HIGH

Evening

Grass LOW

Tree LOW

Weed HIGH

Species	Level	Count
🌿 Giant Ragweed	HIGH	15 grains/m³
🌿 Common Ragweed	MED	12 grains/m³
🌿 Mugwort	MED	11 grains/m³
🌾 Cock's-foot	MED	7 grains/m³
🌾 Perennial Ryegrass	MED	7 grains/m³
+35 more tracked Timothy Grass Grass (mixed) Sagebrush Stinging Nettle Pigweed Fat Hen Russian Thistle 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
🌿 Giant Ragweed	HIGH	20 grains/m³
🌿 Common Ragweed	HIGH	17 grains/m³
🌿 Mugwort	HIGH	16 grains/m³
🌾 Perennial Ryegrass	MED	11 grains/m³
🌾 Timothy Grass	MED	11 grains/m³
+35 more tracked Grass (mixed) Cock's-foot Sagebrush Russian Thistle Stinging Nettle Pigweed Western Ragweed Fat Hen 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
🌿 Giant Ragweed	HIGH	20 grains/m³
🌿 Common Ragweed	HIGH	17 grains/m³
🌿 Mugwort	HIGH	15 grains/m³
🌿 Sagebrush	MED	6 grains/m³
🌾 Perennial Ryegrass	MED	6 grains/m³
+35 more tracked Grass (mixed) Stinging Nettle Pigweed Fat Hen Cock's-foot Timothy Grass Ribwort Plantain Russian Thistle 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
🌿 Giant Ragweed	MED	13 grains/m³
🌿 Common Ragweed	MED	11 grains/m³
🌿 Mugwort	MED	10 grains/m³
🌿 Sagebrush	LOW	4 grains/m³
🌿 Russian Thistle	LOW	4 grains/m³
+35 more tracked Stinging Nettle Pigweed Western Ragweed Fat Hen Ribwort Plantain Cock's-foot Perennial Ryegrass Timothy Grass Grass (mixed) 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	HIGH
Thu 3 Sep	LOW	MED	HIGH
Fri 4 Sep	LOW	LOW	MED

Map of Hillingdon (51.58305°, -0.501246°)

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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