Harrogate's coronavirus infection rate is at its highest level since the start of the pandemic, figures show, and is expected to rise further.
The district's weekly rate on 3 January was 387 cases per 100,000 people - a fourfold increase from just over two weeks ago.
The sharp rise is mirrored across the country and North Yorkshire, and local health bosses have said they expect case numbers to rise further until the effects of the lockdown are felt.
per 100,000 people
Louise Wallace, North Yorkshire's new director of public health, said people should assume the new, more transmissible, variant of Covid-19 was in North Yorkshire and obey the lockdown rules.
"We need to remember that coronavirus is spread through contact," she said. "We are under national restrictions that mean people must stay at home.
"When we do leave our homes, it must be for a justifiable reason and we must all adhere to strict social distancing and wear our face coverings.
"My key message is please stay home and stay safe."
Harrogate's previous infection peak was 302 cases per 100,000 people on 9 November, according to Public Health England data.
The latest figure (387) is below the England average of 608 cases per 100,000. The North Yorkshire average is 399.
Richard Flinton, chair of the North Yorkshire Local Resilience Forum, which includes county and district councils, the NHS and emergency services, said the national lockdown was "needed" to protect the most vulnerable whilst the vaccine roll-out is accelerated.
"This is a time for us to provide stability while our colleagues in the NHS roll out the vaccine," he said. "We have that light at the end of the tunnel of the vaccine, so people need to embrace this lockdown, to comply with the rules.
"This would be a terrible time to lose a loved one when the end of this pandemic is in sight. We just need to work together for a little bit longer, follow the rules and stay at home."