Ms Murray said that a band of tropical air over the region was responsible for the warm weather.
"People may struggle to sleep on Friday with an overnight low of 20C."
The weekend will again be sweltering before the rain arrives late Sunday afternoon - just in time for the Simply Red Concert at Mission Estate.
The south-easterly shift will bring showers to signify the end of summer, she said.
The first week of March is set to be a wet one.
Federated Farmers provincial president Will Foley said Hawke's Bay farms have dried out to normal February conditions expected at this time of year.
"Everyone should be comfortable with feed levels and very relieved El Nino conditions haven't occurred so far."
Mr Foley said that the relatively kind conditions for the past few months have gone some way to offset the negative sentiment around low dairy and lamb prices.
Tropical Cyclone Winston, which has left a trail of destruction in Fiji, is beginning to track south towards New Zealand.
The category four storm has killed at least 20 people and produced winds as strong as 296km/h.
Ms Murray said the cyclone could bring strong gusts to the region this weekend with the potential to cause structural damage.
However there was still a lot of uncertainty surrounding the storm. "We will be keeping a very close eye, and will send out warnings accordingly," she said.