Runners are in for a tough time this weekend as changeable Spring weather presents challenges for the ASB Auckland Marathon.
The marathon is scheduled to take place this Sunday, with runners starting in Devonport and making their way across the harbour bridge to the city, out to St Heliers Bay, before turning around to finish at Victoria Park.
But a ridge of high pressure may make it tough going for competitors, bringing in tropical air and humidity to the east of the country.
"Some places will get clear blue skies, light winds, and the chance of an afternoon shower. Others end up with 'anticyclonic gloom' - when moisture is trapped under the high, which causes cloud and humid conditions," Metservice meteorologist Tom Adams told Newshub.
"By Sunday we see a flux of air flowing down from near Fiji, which will mean a sticky day for runners in Auckland.
"By the start time of 6am participants can expect temperatures of around 14C and 90 percent relative humidity in a light north-easterly."
Organisers are encouraging competitors to be prepared for all conditions and keep an eye on the weather.
"Athletes are advised to ensure that they are sufficiently hydrated for whatever the conditions, and are welcome to carry water or a replacement fluid with them in a bottle or a back pack if that is their preference," Auckland Marathon Media Manger Andrew Dewhurst said.
"As always, common sense is advised, but runners will have fantastic support at all the aid stations and along the route from the marshals and medical teams."
Across the course there will be multiple aid stations all of which will be well stocked with PowerAde and water.
A number of the stations will also have flat coke, which Mr Dewhurst says will be helpful for runners toward the end of the race.