Keyser said the scorching temperatures were down to north-westerly winds moving down from the Kaweka range.
"When you get wind from a high altitude to a low altitude, it's called a foehn wind which is a type of dry, warm, down-slope wind that occurs in the lee of a mountain range.
"Around the world it's known to cause a temperature increase, and now we're seeing it happen here."
Wednesday's high would encourage Bay residents to hit the beach, reaching at least 26C, while Thursday's high was predicted to be 28C.
However, Niwa scientist Ben Noll said Thursday's temperature would boil over 30C.
"If you're in Napier you're certainly going to want to be at the beach, it's certainly going be feel summer-like in the short-term."
After monitoring weather patterns during the course of October, Noll said Hawke's Bay had significantly less rainfall compared to other years.
"It's a concern from an agricultural perspective because obviously farmers need the water and October can be a bit of an early start, especially when things are starting to dry out, so they have every right to be concerned."
Noll said things would continue to heat up during the month of November, especially this week.
"It's going to be an absolute scorcher, the heat is going to be in full-effect with all this warm air coming over from Australia.
"This is a pattern that is going to come with below average rainfall for the next couple of weeks, so the soils and water conservation are of growing concern."
Federated Farmers president Jim Galloway said Hawke's Bay farmers were no stranger to hot and dry weather and were usually well prepared.
"The biggest thing to do in these situations is making decisions early, if you have to get rid of stock so you've got enough feed for the ones left.
"I think most people that have been here for a little while have been through dry periods of droughts. The biggest thing for us to realise is that we're not the only ones in this situation.
"It's important to communicate with one another, that's really important for the mental health side of things, talk to your bank if you have any financial concerns."
Galloway said as well as Federated Farmers, there were a number support networks such as the Rural Support Trust and Farmstrong, which were available to offer ongoing assistance to those who needed it.
