Elsewhere around the North Island, pharmacists report an increase in symptoms related to hay fever.
Allergy specialist Vincent St Aubyn Crump said he had heard anecdotal evidence from patients that pine-tree pollen season had started.
Dr Crump said New Zealand's pollen season lasted about 34 weeks and varied in its timing, starting in July or August with pine trees and continuing into August/September with deciduous trees such as oaks, elm and birches. Grasses were the major pollen hazard for allergy sufferers, usually from October to Christmas and beyond.
"Pine pollen is a significant irritant even for those who are not allergic to it. The pollen is often noticeable because of the yellow colour as it coats surfaces in the area," he said. "However, pine trees have a short pollen season - about two weeks - so if people continue to experience allergy symptoms, such as hay fever, then it is likely they are reacting to other tree pollens and to grasses, which would also indicate an earlier pollen season for these as well."
Allergy New Zealand says the two main types of allergic rhinitis (hay fever) are seasonal and perennial. While seasonal hay fever was usually triggered by wind-borne pollen, perennial hay fever persisted all year, triggered by house dust mites, pets or mould.
Meanwhile Philip Duncan, of WeatherWatch, said spring had arrived early.
Mr Duncan cautioned against getting hopes up for an early summer, but said warmer-than-average temperatures were likely for the rest of August and September.