Pollen is moderate in HA (Harrow) today.

HA covers part of Greater London and follows its regional pollen pattern closely.

Tree pollen here is dominated by London plane, oak and lime, with grass led by ryegrass and cocksfoot and weeds by nettle and mugwort.

Tree pollen typically peaks in late March to early May. Grass counts are highest from late May into early July. Mature urban canopy with high plane and lime cover keeps the tree count active well into May.

For the wider regional view see Greater London.