A team of hornblowers are to work from home as part of efforts to contain the spread of coronavirus.
A horn has been sounded four times in Ripon's Market Place every night at 21:00 BST since AD886 to "set the watch".
The tradition will now take place behind closed doors after the government issued strict new guidance.
The council said the change meant the ceremony would still take place within the city boundary.
The last time hornblowing in Ripon faced such serious disruption was during the Second World War.
In a statement, the council said: "Given the extraordinary situation that the whole country and wider world finds itself in, our hornblowing team will now undertake the setting of the watch ceremony from their home address within the city boundary."
The tradition is said to have begun following a visit to the city by Alfred the Great who urged residents to be more vigilant and gave a horn to the city as a symbol of it being granted a Royal Charter.
The ceremony attracts scores of people each night during the summer.
On Monday Prime Minister Boris Johnson said people should leave home only to exercise once a day, travel to and from work where "absolutely necessary", shop for essential items and to fulfil any medical or care needs.
Ripon City Council said hornblowing had been amended before including during the blackout when it was moved to earlier in the evening.
The hornblowing team - made up three men and one woman who share the public duty - will confirm on Facebook each evening that the watch has been set.