"There is a ridge of high pressure behind this cold front, which leads to plenty of clear skies and light winds."
Temperatures will be even lower tonight , with a low of -1C as there won't be much cloud to provide insulation. Although, it is set to be one of the better days, with cloudy periods, a chance of morning showers and easterly breezes.
"There will be widespread frosts and there could be black ice on roads as well, so take care if you're driving," James said. For the rest of the week, overnight temperatures remain at 7C.
This ridge remains over Aotearoa through to the end of today .
He said people will notice a deteriorating trend in the weather during the week.
"Later in the week, New Zealand is affected by a series of fronts and troughs, so things get a little bit unsettled with on and off scattered rain from Wednesday."
Thursday and Friday will see some rain developing, but clearing later, along with gusty northwesterlies.
Niwa Principal Scientist Chris Brandolino said winter has been "dry so far".
Only 17.4mm of rain has fallen from August 1-16, well below the normal 54mm for the month.
Brandolino said this is dry for August.
As for daytime temperatures, Brandolino said they have been "most unusually warm" so far in Hawke's Bay through to mid-August.
During the same timeframe, the mean temperature has been 10.6C in Napier, 0.9C above average.
16.0˚C is the mean max temperature so far for Napier, 1.5˚C above average and considered "well above average".
The mean minimum temperature (to 17 August) for Napier is 5.2˚C - near average at 0.3˚C above average.
He said the lack of rain aligns with lack of cloud.
"Therefore, with nights still longer than daytime, and a lack of rain (and presumably cloud) temperatures are allowed to cool," he said.
"However, during the day, lack of rain (and presumably lack of cloud), we have sunshine to warm things up. Also, we've seen westerly winds this month, and that is a warm wind for Hawke's Bay as it descends off the Central Plateau (air that descends or sinks warms by compression)."
Brandolino, however, said we're likely to see better chances for rain during the second half of this month.
Federated Farmers president Jim Galloway said it has been a "reasonably good winter".
With the conditions being "nice and dry", it has helped with stock grass utilisation, in turn, "helping the stock grow".
"We are at a reasonable place at the moment, so we've just got to hope that we don't get one of those big storms come through as that can upset things if that does happen," Galloway said.