In winter Rotorua's Blue Lake is quiet, foggy and empty.
But today that wasn't the case as about 40 staff from Scion took part in the company's annual polar plunge.
The annual swim in Tikitapu (Blue Lake) usually takes place on the shortest day of the year but this year took place the day before, so as to be on a weekday.
It started in 1996 as a challenge between two social groups at Scion, known then as Forest Research Institute.
Forty staff dressed in costumes ranging from chefs to ballerinas took part in the plunge.
Harnett said this was the third time she'd been crazy enough to participate and it was colder than last year.
Research officer Garth Weinberg has only missed two of the 24 plunges over the years and said it was kind of like the Wednesday of the year.
"It's about getting everyone together marking the shortest day of the year. It's like reaching Wednesday, the days are going to get better and longer from here."
Rikimata Massey described the water as "fresh".
"It's something to break up the year a bit. It adds a little bit of fun especially as the days are shorter."
After the cold water the team warmed up with mulled wine and hot chocolate.
Staff at Scion's Christchurch branch have been doing the plunge in the ocean for three years.
Tomorrow is the shortest day of the year, with the sun in Rotorua due to rise at 7.31am and set at 5.02pm, giving just nine hours and 30 minutes of daylight.
It's five hours and 19 minutes less than the longest day of the year when the sun rises at 5.48am and sets at 8.37pm.
MetService meteorologist Stephen Glassey said the average minimum temperature in June was historically 4.3C and this month had been similar with a mix of days above and below the average.