The child was named Sienna but quickly earned her own social media hashtag “#A66snowbaby”, referencing the name of the road in northern England where her mother Daniella Waring gave birth on Thursday morning with the help of her husband Andrew, after heavy snow impeded their dash to hospital.
“The weather was very bad and I struggled to find somewhere to pull over and barely had time to ring 999 (emergency services) when the baby started coming,” Andrew Waring said, according to details released by Great North Air Ambulance service.
“Having been present at the birth of our two other children I just copied what I had seen then.
“I opened the passenger door and knelt in the snow to deliver the baby.”
Paramedics arrived soon after and tended to mother and newborn before rushing them to Darlington Memorial Hospital maternity unit.
There, Sienna Louisa Dottie Waring weighed in at a healthy 10lbs 1 oz (4.6 kg) and was “doing really well”, according to staff.
Britain — and most of Europe — has been gripped by extreme cold weather and major snowfall throughout the week.
“The conditions were challenging to say the least and we initially had difficulty finding the family,” said air ambulance crew member Philip O’Donnell.
“The baby had arrived shortly before we arrived so the hard work had been done, but we were able to check baby and mum over before the ambulance crew arrived and took her on to hospital.
“It was a lovely job to be involved in and we’d like to congratulate them on the new arrival.”
Anne Hodgson, labour ward sister at Darlington Memorial Hospital, said the newborn was being cared for in a special cot which has a mattress filled with warm water to regulate her temperature, and was regularly monitored throughout Thursday.
“Daniella and Sienna had been in freezing temperatures so our priority was making sure they had skin to skin contact to warm Sienna up,” she said.
“We have no cause for concern and they’re both doing really well despite their experience.”
Sharing details of the episode on social media, the air ambulance crew christened the new baby with her first hashtag.
“Sienna Louisa Dottie Waring, born by the side of the A66, welcome to the world!” they wrote on Twitter.