Grass
Very low
Index value 1 of 5.
Grass active.
Saturday 15 August Updated 23:57
Pollen is very low in Treharris today.
Tomorrow stays at this level.
Tree
None
Index value 0 of 5.
Weed
Very low
Index value 1 of 5.
Treharris sits in Merthyr Tydfil County Borough and takes its pollen pattern from the Wales forecast region. Around 12,400 people live here. Hay fever sufferers should track all three pollen types from March through August.
Tree pollen here is dominated by oak, birch and alder, with grass led by ryegrass and cocksfoot and weeds by nettle and dock.
Tree pollen typically peaks in April. Grass counts are highest from June. Mountain rain can clear the air quickly but valley pockets see persistent grass counts in June.
For the wider regional view see Wales, or browse every area we cover.
Hay fever season in Treharris
The pollen season in Treharris runs from February to October. The worst months are typically April, June, July and August.
| Pollen | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tree pollen | Jan: none | Feb: low | Mar: active | Apr: peak | May: active | Jun: low | Jul: none | Aug: none | Sep: none | Oct: none | Nov: none | Dec: none |
| Grass pollen | Jan: none | Feb: none | Mar: none | Apr: none | May: low | Jun: peak | Jul: peak | Aug: active | Sep: none | Oct: none | Nov: none | Dec: none |
| Weed pollen | Jan: none | Feb: none | Mar: none | Apr: none | May: none | Jun: low | Jul: active | Aug: peak | Sep: active | Oct: low | Nov: none | Dec: none |
- Tree pollen in Treharris runs from February to June. It peaks in April.
- Grass pollen in Treharris runs from May to August. It peaks in June.
- Weed pollen in Treharris runs from June to October. It peaks in August.
See the full UK pollen calendar or read when hay fever season starts and ends.