Fast-rising Kiwi track star Sam Tanner went from sweltering summer temperatures at home to 'minus-15 degree'' cold in Boston to run the third-fastest mile in New Zealand men's athletics history.

The 22-year-old from Papamoa clocked 3min 52.85sec at the New Balance Indoor Grand Prixin Boston on Saturday (Sunday NZ time).

Olympic Games medallists John Walker and Nick Willis are the only Kiwi milers to have run faster than Tanner, who has now eclipsed Olympic legends Peter Snell and Rod Dixon, plus past New Zealand representatives Zane Robertson and Adrian Blincoe.

Tanner says in a post-race video interview with Let's Run.com that he decided to go all out because he was 'afraid to travel halfway across the world and run 3:54 like I could do at home''.

Just eight days before his Boston race, Tanner had set a new personal best of 3min 54.56sec in winning the New Zealand mile title at the Cook's Classic meet in Whanganui.

He shaved a further 1.71sec off that mark in finishing second to Scotland's Neil Gourley at the New Balance meet.

Tanner says it had been 'a pretty quick turnaround'' after arriving in Boston last Wednesday following 'a 20-hour flight''.

But he says he 'slept like a baby” for eight or nine hours in the air after getting 'a cheeky upgrade''.

'Travel doesn't affect you, [unless] you keep it in your head,'' he quipped.

But the New England winter took some adjusting to.

Tanner reckoned it was '85 degrees [Fahrenheit] at home'' when he left and was 'negative 15 Fahrenheit'' in Boston.

'My face got frostbite,'' he laughed.

He went on a warmup run 'fully wrapped up'', saying: 'They breed us tough [in New Zealand], but not that tough.''

Tanner's soaring form is no surprise.

He was already New Zealand's second-fastest male 1500m runner of all time – behind Willis (3min 29.66sec) – after clocking 3min 31.34sec in finishing sixth in the Birmingham Commonwealth Games final last year.

Tanner will stay in the United States for the feature Wannamaker Mile event at the Millrose Games in New York next weekend.

He will resume his rivalry with Gourley there after the Scot 'got one up on me'' in Boston after the pair had been locked at '2-2'' in their four previous races.

Gourley finished strongly in Boston to move from third to first and pip Tanner on the line, to win in 3min 52.84sec.

Tanner will also get to chart his improvement against Birmingham 1500m champion Ollie Hoare, the Australian who will be defending his Millrose Games mile title.

It's already been quite a summer for Tanner, who affiliates to Ngā Puhi.

He slashed 45sec off his 5000m personal best in finishing second in 13min 32sec at the Night of 5s meet in Auckland a week before Christmas.

AT A GLANCE

New Zealand's three fastest male milers (outdoor or indoor)

1: John Walker, 3min 49.08sec (1982).

2: Nick Willis, 3min 49.83sec (2014).

3: Sam Tanner, 3min 52.85sec (2023).

- Stuff.