Australian asthmatics are on notice to get set for peak thunderstorm asthma season, as the La Nina weather event also puts allergy sufferers at risk.
The peak thunderstorm asthma season is set to take hold from October 1 until the end of December, according to the National Asthma Council.
Australia has one of the world's highest rates of asthma with one in 10 affected, and it's high time for asthmatics to check in with their general practitioners and make sure they are on the best treatment possible, council director and respiratory physician Professor Peter Wark said.
It is also important that asthmatics know what to do in a spring thunderstorm or asthma emergency.
"Good asthma control is critical during thunderstorm asthma season, so keep taking your preventer medication as prescribed by your doctor," Prof Wark said.
The respiratory physician also had a stark warning for those allergic to ryegrass pollen.
The La Nina event underway in the Pacific Ocean will increase the likelihood of above-average rainfall in eastern Australia, which may lead to above-average grass growth and more ryegrass pollen in the air.
People with hay fever and an allergy to ryegrass pollen could be at risk of thunderstorm asthma even if they had never before had asthma symptoms.
"If you are allergic to ryegrass pollen, you could have a severe asthma attack if you are outside in gusty winds just before or during a thunderstorm in spring or early summer in a place where there is ryegrass pollen in the air, which includes most of south-eastern Australia," Prof Wark said.
He suggested people with hay fever regularly use a nasal corticosteroid spray every day, while those who needed a reliever more than a couple of times a month should take a preventer.
Asthmatics should also make sure their action plans were up to date and included thunderstorm advice, avoid being outdoors during thunderstorms in spring or early summer, and monitor pollen counts and weather forecasts.
They should also always carry a reliever puffer and replace it before its expiry date.
In November 2016, Melbourne experienced the world's largest epidemic thunderstorm asthma event, overwhelming emergency services and leading to 10 deaths.
Among those affected by the epidemic were people with seasonal hay fever who had not ever had asthma.
The Bureau of Meteorology declared a rare third consecutive La Nina weather event earlier this month.
