Hawaii Allergy Season Guide

Hawaii experiences a tropical climate with consistent warm temperatures, trade winds, and a wet-dry seasonal pattern that varies by elevation and island side.

Grass pollen — especially Bermuda, paspalum, and Johnson grass — is the dominant year-round trigger. Tree pollen is less seasonal than on the mainland, with eucalyptus, mango, and ironwood active throughout the year.

Persistent tropical humidity supports very high year-round mold counts, particularly Cladosporium, Alternaria, and Aspergillus.

Allergy patterns vary by elevation and proximity to coast or mountains within Hawaii, but most of the state shares a common seasonal rhythm of spring tree pollen, summer grass pollen, and late-summer to fall weed pollen.