Thirty-five motorcyclists have died on Victorian roads so far this year, an increase of 75 per cent from the same time last year.
Police are concerned about the spike, which represents a 56 per cent increase above the five-year average of 22.6 deaths, just six months into 2024.
Cooler weather typically leads to a drop in motorcycle activity, but Victoria Police said that was not the case this year.
"It was the deadliest May for motorcyclists in 10 years," police said in a statement on Friday.
Eight rider fatalities were recorded in that month alone, compared to none the previous May.
There have been five motorcyclist deaths so far in June, compared to three at the same time in June 2023.
Motorcycle deaths on regional roads have more than tripled to 16 this year, while most rider deaths continue to happen on metropolitan roads, up to 19 from 15 last year.
Two in five riders killed on the roads were aged between 18 and 35.
Road Policing Assistant Commissioner Glenn Weir said it was concerning that motorcyclist road trauma had risen so significantly.
"We've identified failing to give way, from both riders and drivers, and inappropriate speed as major contributing factors to this year's motorcyclist fatalities," he said.
Police will ramp up enforcement, with a special operation in the bayside suburbs of Kingston, Glen Eira and Bayside, where rider deaths spiked from zero last year to five so far in 2024.
"We need all road users to play their part to help keep each other safe, particularly at this time of year with poor visibility and wet, slippery roads," Mr Weir said.
The Traffic Accident Commission says 137 people have died on Victorian roads in 2024.
This included 16 deaths so far in June, while pedestrian deaths have almost doubled to 23 compared to 12 at the same time in 2023.
TAC acting chief commissioner Andrew Holt said it was critical for road users to put safety first by slowing down, resting before a road trip, separating drinking from driving and putting their phones away.
"We can all make a difference if we make safe choices," he said.
