Hayfever, allergy sufferers warned of a sniffly summer with perfect conditions for pollen-producing plants

Hayfever and allergy sufferers are being warned you might need to prepare for a sniffly summer.

La Niña is expected to bring humid, rainy, and windy weather throughout the season and that means perfect growth conditions for pollen-producing plants.

If you've been feeling particularly sneezy or wheezy it could all be to do with something called La Niña.

The complex weather pattern involving ocean temperatures happens in the equatorial Pacific but La Niña has flow-on effects for our weather here.

"La Niña has meant that our spring temperatures have been quite warm here in New Zealand and it's also come with abundant rainfall across the North Island, upper South Island," says NIWA meteorologist Ben Noll.

And with pollen-producing plants thriving in the humid and rainy conditions, it's bad news for hayfever and allergy sufferers.

Pharmacist Tzu-Ming Wang says hayfever-easing products have been in demand.

"Every spring it's kind of the same, but definitely seen a big influx two to three weeks ago."

We've already seen the effects of La Niña on our spring weather. October temperatures were higher than usual - 1.2C above average across the country.

And NIWA says the humidity, warmth, and rainfall are going to stick around for summer too. That means allergy and asthma sufferers might need to be mindful of more pollen.

"People ringing up us and saying, you know, their allergies are just really bad at the moment and of course that does worsen their asthma symptoms," says Asthma and Respiratory Foundation NZ CEO Letitia Harding.

The Asthma and Respiratory Foundation is reminding New Zealanders to check and pack their asthma medication before travelling around the country this summer.

"What you're used to with your asthma and your allergies say in Auckland may be different when you're heading down the South Island," Harding says.

Keeping allergies at bay to enjoy a La Niña summer relatively sneeze-free.