Some 933 such incidents were recorded across England, an increase of 194 on the previous year, the Fire Brigades Union said.
It also highlighted figures showing the loss of 500 firefighting jobs in the last year, which it said had left services “struggling” and meant that crews were taking 30 seconds longer than in 2010 to reach callouts.
The union’s general secretary, Matt Wrack, said it was “despicable” that anyone would attack firefighters, adding: “Cuts by this Government have led to the demolition of community engagement projects, which are proven to reduce anti-social behaviour. Investment in these services is urgently needed across the board.”
In the latest incident, firefighters in Sheffield were pelted with fireworks, eggs and other missiles when they responded to a house fire on Halloween.
South Yorkshire Fire and Rescue said the blaze in the Tinsley district was caused when a firework was deliberately thrown into the terraced property. A group of youths confronted the fire crew as they arrived.
No-one was injured, but the service’s area manager, Tony Carlin, said: “We are absolutely appalled that our firefighters appear to have been targeted in this way.”
Mr Wrack accused the Government of “playing with lives” over fire safety.
He said: “Last week, the Chancellor announced the biggest spending spree this Government has been on, yet not a penny will be seen by the Fire and Rescue Services who need it.”
He added: “This weekend, families up and down the country will enjoy firework displays, yet there are fewer firefighters to keep people safe. The Government must take seriously the need for investment and more firefighters in our communities.”
Other emergency workers have also seen an increase in levels of violence, and new legislation which introduces tougher sentences for offenders, came into force this month.
Earlier in the week, the Health Secretary, Matt Hancock, announced what he called a “zero tolerance” approach to violence against NHS staff – around one in eight of whom experienced violent behaviour in the last year.
Unveiling the first NHS “violence reduction strategy”, Mr Hancock said a new partnership between the NHS, police and prosecutors would put offenders before courts more quickly.
“I have made it my personal mission to ensure NHS staff feel safe and secure at work,” Mr Hancock said.