Hastings could reach 32 degrees on Saturday and Napier 31 degrees.
Sunday brings a potential for very light rain in the evening and high cloud, he said.
The higher than usual temperatures are showing no sign of slowing down as summer continues.
Hawke's Bay Regional Council's Principal Climate Scientist, Dr Kathleen Kozyniak, says the outlook is for the warmer than usual temperatures to continue.
"The general pattern is for the westerlies to remain with us for December, but ease after that and probably take on more of a northerly airflow," Kozyniak said.
With water restrictions already in place in many of Hawke's Bay's urban areas, rural areas are also starting to feel the heat, with take bans on some rivers being introduced.
There are currently restrictions and bans on taking water from 10 rivers and streams across the region with the prospect of more restrictions being imposed soon.
Weather of this kind also brings a higher fire risk, MetService said. Restricted fire seasons are in place in the Wairoa District and Central Hawke's Bay.