Paul Anderson operates Indigo Restaurant and said on Tuesday night he had 24 people looking to be seated outside.
"But I had to turn them away as with the cricket being on the inside was fully booked."
He estimated he was losing $1500 a night, during the three-week council "vanity job".
A job he said could have been carried out before the summer.
Anderson said he and other businesses had just come out of six months of disruption, and estimated that had cost him up to $100,000.
The income from summer effectively set his and a neighbouring restaurant up for the quieter times of winter, so the latest disruption was another ill-timed blow.
Trass believed the lighting work should have been done during the previous upgrade.
"It doesn't make sense."
Napier City Council marketing and communications manager Craig Ogburn said the lighting was intended to be installed during the street upgrade but time ran out.
"It got too close to Christmas so it was decided that it be delayed."
He said the work needed to be carried out now because the new lights were Art Deco style and needed to be up and glowing by the time the Art Deco Festival kicked off on February 13.
"It has to be done now. And being Art Deco style it will draw people there so will be a benefit in the long term."
Trass said affected business owners he had spoken with said they were contacted by email at 11am on Tuesday — when the work was already under way.
Ogborn said the council's regulatory team was in contact with business owners and would meet them to discuss what was happening. He said the lighting would be an additional attraction to the area when completed. For now, it was a three-week major lull in business, Anderson said.