Sixteen persons died when a coastal freighter and a rescue boat were wrecked off the southwestern tip of England overnight in hurricane-force gales as winter storms again battered Britain.

Nearly 30 persons have been killed in the worst December weather of this century. The gales, blizzards and severe cold began two weeks ago, and another blizzard blanketed much of the country outside the London area today with heavy snow, driven by high winds. After several persons died when trapped in deep snowdrifts a week ago, teams were out early last night.

The tragedy at sea occurred when a new British-owned coastal freighter, completed only 10 days ago in a Danish shipyard, became disabled in high winds and seas off Cornwall. On board were British officers, Portuguese sailors and the South African wife of the ship's master and her two teen-age children.

A lifeboat from nearby Penzance, manned by eight volunteers from the small fishing village of Mousehole, managed to rescue four persons from the freighter, according to radio messages, before the freighter overturned, and the lifeboat broke up in the heaving seas.

The all-volunteer lifeboats are revered commmunity institutions along the coast of Britain, supported by nationwide charitable appeals. Two other lifeboats searched in vain during the night for survivors before the bodies were found today.

The last two weeks' storms, among the worst in a pattern of harsh early winter weather in northern Europe, cut off remote regions of the country and blacked out tens of thousands of homes for days. In southwestern England, flooding from high tides and a sudden thaw between blizzards last weekend drove hundreds of families from their homes and killed farm animals.

Britain was especially unprepared for the heavy snows and extreme cold. In London and southern England, temperatures seldom fall far below freezing and snow is rare.

Clearing of roads and airport runways was slow, stranding travelers much of last weekend. Car radiators froze because they contained no antifreeze. Heavy snows stopped trains, broke power lines, felled trees and, for one day, froze the hands on Big Ben outside Parliament. The queen was among 100 motorists forced to take shelter in a small Cotswold Hills hotel during a blizzard last weekend, which caught her on her way back to Windsor Castle from a visit with Princess Anne and Capt. Mark Phillips.

Newspapers here have made comparisons with previous severe winters in British history, which seem to have occurred most often in the eighties of each century. The frigid winter of 1683-84 occurred at the peak of what climatologists call Europe's "little ice age."