Thunderstorm asthma is a recurring public health emergency in South-Eastern Australia which occurs in springtime. The major identified risk factors for thunderstorm asthma is hay fever and allergy to ryegrass pollen. The goal of the CARISTA study is to identify the risk of springtime allergic and thunderstorm asthma in allergic adults living in South-Eastern Australia. To do this the investigators will recruit 530 people who have hay fever and test them for allergy to ryegrass pollen and undertake simple lung function testing. The investigators will ask study participants to complete a customised symptom tracker over the springtime pollen season for 2 consecutive years. The outcome the investigators are looking for is an asthma exacerbation or worsening asthma symptoms. This study will enable the investigators to identify indicators (biomarkers) of severe and moderate asthma exacerbations in order to identify those at risk of thunderstorm and seasonal asthma so protective treatments and strategies can be advised.