Not such great news for all you hayfever sufferers - today was the first high grass pollen day of the season! A high day is one where there was an average of 50 or more grass pollen grains per cubic meter of air for the previous 24 hour period. We identify grass pollen by the presence of a single pore (the pore is arrowed in the photo). Still lots of tree pollen too, mostly cypress. Forecasting another high grass pollen day for tomorrow as well.