But 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.

For the second year, the team behind the Canberra Pollen count used data gleaned from more than 20,000 responses from 11,000 users of the phone app to create a map of the suburbs most likely to leave hay fever sufferers searching for a tissue.

The worst symptoms were experienced in Casey, Forde, and Franklin in Gungahlin; Melba, Holt and Higgins in Belconnen; Dickson and Reid in northern Canberra; and Macarthur, Gilmore, Isabella Plains and Calwell in Tuggeranong.

App users ranked their daily hay fever symptoms from "none" to "severe" on a scale of one to five during the 2014 and 2015 hay fever seasons.

Professor Haberle said most of the suburbs were also hotspots last year, suggesting there may be some areas that hay fever sufferers and asthmatics should avoid.

"It confirms that this is not just a random distribution, there's actually strong meaning in the hotspots we've found … we really are seeing a pattern," he said.

"We've just got to work out now what the significance of the data is."

But it's still unclear why some areas are worse than others.

Environmental factors are the most likely cause with the open pastures near Gungahlin, Belconnen and Tuggeranong suburbs and pine plantations near Macarthur, Gilmore, Calwell, Holt and Higgins.

While highly allergenic street trees such as the plane tree and oak are likely to be the reason inner-city dwellers in the suburbs of Reid and Dickson spent spring sneezing.

Suburbs marked in red are those where respondents reported the highest levels of hay fever suffering throughout the season. Suburbs marked in blue show a strong negative deviation from the mean, implying low levels of hay fever suffering across the season.

"I've looked at things like socioeconomic indicators and there doesn't seem to be any correlation, so it's really back to the environmental conditions," Professor Haberle said.

"If you know where they are and you're visiting you know you might be affected more in that area than another."

Last year six ACT and two Queanbeyan suburbs were considered hotspots for hay fever including Casey, Franklin, Reid, Gilmore, Isabella Plains and Calwell and across the border in Karabar and Jerrabomberra.

Professor Haberle said the team would now look to overlay a map of plant species to see if there was a correlation.

"We looking to drill down into this … to see how we can improve the landscapes of Canberra to reduce things like hay fever and asthma being a problem by advising landscape designers and the people building new suburbs so they can be aware of this sort of information and use it in the planning process," he said.

"The legacy of those older plantings is now coming to fruition with allergy problems.

"I wouldn't advocate cutting trees down but at least it's making people aware if they are sensitive they should try and avoid them."