It was a chilly start to the day in Rotorua where residents experienced their first real frost of the year this morning - but temperatures will warm up a little before winter really hits.
MetService communications meteorologist Lewis Ferris said there was a weak frost on April 18, but this morning was "more convincing".
"Another cool start is expected tomorrow with a low of 4C, warmer than the -0.2C low today, but we're now on the warming side thanks to a shift in wind flow, with lows around the 6 to 8C mark," he said.
Afternoon highs in Rotorua will be in the 16 to 19C range which is just above the usual May average of 15.4C.
There was also a possibility for morning fog during the coming days.
Ferris said Taupō was in the same boat temperature-wise while Tauranga and Whakatāne were a touch warmer with highs in the low 20s.
He said the next two weeks were forecast to run above average in terms of temperature with this week looking dry but next week a little wetter.
"It may seem obvious heading into winter but with the lengthening nights, frosts will become more likely and those afternoon highs won't be as warm.
"Winter brings the risk of cool outbreaks from the south. Rotorua Airport is about 50mm below where it would usually be for this time of year but winter tends to be the wettest season."
Bay of Plenty lows this morning: