Seasons

According to the National Health Survey 2022, over 1 in four Australians 23.9% had Allergic Rhinitis (AR or hay fever) in 2022:

You can access AR prevalence for each state/territory in the data downloads, Tables 28 to 35, from 2001 to 2022

According to AIHW asthma report 2024 (ref 1), the peaks for asthma hospitalisations generally occur for children:

• in late summer (February): the peak in February is related to respiratory infections spreading with return to school and childcare after the summer break, and possibly a lower use of preventer medicines during the summer break
• in autumn (May)
• One-off natural events occurring on a seasonal basis like bushfires and thunderstorms can also impact asthma hospitalisations

2020 was an exception to this general trend, with a large decrease in hospitalisations in April and May for all age groups, due to COVID measures and lockdowns.

Figure 16: Monthly variation in hospitalisations due to asthma, by age group, 2017 to 2021 (ref 1)

Refer to Fig 16 on AIHW website to obtain exact hospitalisation rates per months and age groups.

Each year is a different NHS survey, need to go into past and future releases, and download the data for each one.

30% of people who were impacted by thunderstorm asthma, had never had asthma symptoms before.
Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m3). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74–2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28–16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died.

– Over the two days of the event (21-22 November 2016), 9909 people presented at public hospital emergency departments in metropolitan Melbourne and Geelong. This includes all presentations, not just asthma/respiratory related ones. This was a 58% increase on the three year average.
– There were 2,953 presentations to public hospitals in Melbourne and Geelong which were coded as ‘respiratory diagnosis.’ This was a 556% increase on the three year average, or 2,520 more presentations.
– There were 1,253 ‘nil diagnosis’ presentations to Melbourne and Geelong public hospitals. This was a 300% increase or 940 excess presentations compared to the 3 year average.

19.3% of Australians had allergic rhinitis (one in five) in 2017/18. This has increased from 15.5% in 2001.
The Australian Capital Territory has the highest prevalence of allergic rhinitis.