Canberra could experience up to four days of extreme conditions this pollen season that could trigger a potential thunderstorm asthma event, a leading expert has said.

Despite a brief reprieve from the wintry months this week, Canberra's first week of spring is looking blustery and cloudy, as is much of south-eastern Australia.

The number of serious cases of pollen allergies and hayfever presented to Canberra emergency departments has increased over the past year.

The Canberra region's peak season for pollen is predicted to start about a week early, possibly due to climate change.

Spring has sprung.

Thanks to the ANU's pollen catcher, researchers have been giving hay fever sufferers the heads up on when to expect the worst symptoms, and now through their responses they have pinpointed Canberra's hay fever hotspots.

Canberra's pollen levels are twice as high this hay fever season compared with last year, according to researchers at the Australian National University (ANU).

Researchers studying pollen have found evidence of a phenomenon known as "thunderstorm asthma" in Canberra.

Symptoms for hay fever sufferers usually ease up by summer, but recent thunderstorms and warm days have released fungal spores into Canberra's skies and it's left many allergy sufferers reaching for the tissue box.

Canberra is on track to break a record of the longest string of days with high and extreme pollen levels and hay fever sufferers be warned - the worst could be yet to come.