Napier, Hastings and Wairoa could all expect highs of about 25C on Friday, likely to be the warmest day of the week.
Typical of summer-like weather, though, there may still be a few afternoon showers and even inland thunderstorms across the week, he said.
Fernandes said there was a "moderate thunderstorm risk" for inland Hawke's Bay on Monday, but coastal areas were unlikely to see this.
Meanwhile, drivers across Hawke's Bay have been asked to take care following multiple slips and road damage following recent rain.
Waka Kotahi New Zealand Transport Agency continues to advise caution on both State Highway 5 and State Highway 2, where there are multiple temporary speed restrictions in place.
Slippery surfaces, washouts, heavy rain, uneven road surface and subsidence of the road have been reported in various places across both highways.
Caution is especially advised along SH2, near the intersection with Te Kahu Rd at Raupunga, due to a fallen tree and slip material blocking the road.
Stop and go traffic management is in place, along with a 30km/h temporary speed restriction, and motorists are advised to expect delays.
Police were also called to reports of a slip on SH5, Te Pohue, near Mohaka Bridge, at about 8.15am on Sunday morning where a person had tried to drive over it and became stuck.
There were no injuries reported in the incident.
In Central Hawke's Bay, both lanes of Kairakau Rd have been closed near the 7.1km mark following significant road movement.
Central Hawke's Bay District Council advised detours were in place via Mangakuri Rd, Clareinch Rd, Pourerere Rd and River Rd but to be cautious.
A major roading upgrade is planned for the summer months to resolve the slump in this road.
Mountain bikes at Te Mata Park have also been told to avoid the Te Kahika track which is closed due to recent rain damage.
