Aim: This study measured the frequency and geographical extent of peaks in asthma presentations to emergency departments in inland NSW; it assessed the characteristics of patients who presented at peak presentation times during the rye grass pollination season (October–November) and at other times of the year. Methods: Data describing over 13 years of daily emergency department presentations with a provisional diagnosis of asthma at nine inland NSW base hospitals were assembled. Days of counts in the top 0.1 percentile for each emergency department were classified as peak asthma count days. Results: While the rye grass pollen season accounts for only 17% of days in the year, 53% of peak asthma count days fell within that period. Patients aged over 14 years represented 74% of visits on peak asthma count days during the pollen season and 50% on peak days at other times of the year. Discussion: Under the right climatic conditions, rye grass pollen may be responsible for presentations for acute asthma to emergency departments in inland NSW.