Thousands of people gathered at Stonehenge for a winter solstice which may have taken place on the mildest December 22 since records began.
The Met Office said it was "finely balanced", but sunshine in the afternoon could put the heat on Hoylake's 105-year record for the warmest December 22. The Greater London area is the most likely to beat the record of 16.1C set at Hoylake, Merseyside, in 1910.
A spokesman said: "Generally speaking there's been quite a bit of cloud, but if the sun peeps through the clouds in early afternoon, it could just push the temperature up to 16C or something like that."
A crowd of almost 5,000 people were at the prehistoric Wiltshire landmark for the "very special" time of the latest dawn and the point when the sun is at its lowest in the sky, according to senior Druid, King Arthur Pendragon.
He said: "I think we got about 5,000 people in the summer and we were nearly that and it is winter. It has been a very mild December but throughout the night it was rainy and windy which, in turn, might have put some people off.
"I think a lot of people are looking to nature because of global warming and the environment. They are turning to Earth-bound religions.The winter is a time of renewal and hope.
"I have been going (to Stonehenge) for 30-odd years. It is always very special."
This year's solstice was at 4.49am, and the sun rose over Stonehenge at 8.04am.
The winter solstice is the annual event that marks the point when the North Pole is tilted 23.5 degrees away from the sun.
As a result of the northern hemisphere leaning away from the sun, Tuesday will see the fewest hours of sunlight in a day.
A spokesman for Historic England said people travel to Stonehenge on the winter solstice because of the monument's alignment with the sun. It is believed the solstice was of huge importance to Stonehenge's prehistoric users.
The sun sets between the trilithon, which is where two vertical pillars stand next to each other, supporting a horizontal stone on top.
The Historic England spokesman said: "One of the most important and well-known features of Stonehenge is its alignment on the midwinter sunset-midsummer sunrise solstitial axis.
"The midwinter sun sets between the two upright stones of the great trilithon. We do not know which solstice was more important to the users of Stonehenge, but several pieces of evidence suggest that midwinter was very important.
"Analysis of pig bones at nearby Durrington Walls suggests that feasting was happening here particularly at midwinter."