It won't be as balmy as Southern California, but Washington should offer President-elect Ronald Reagan a snowless and partly cloudy day with above-freezing temperatures for his inauguration next Tuesday.

The National Weather Service, issuing its five-day forecast yesterday, said the day should dawn with the mercury in the low 30s, getting into the low 40s by the noon presidential oath-taking and rising a few more degrees by nightfall. Forecaster Larry Wenzel said there probably will be a northwesternly breeze of 5 to 10 miles an hour.

The official forecast squared generally with the long-range prediction made two days after Reagan's election in November by Washington television weatherman Gordon Barnes. He said then -- and repeated it last night -- that Tuesday should be partly sunny and breezy with a high of 34 to 38.

There is a little chance, the weather service said, of an inauguration day repetition of yesterday morning's storm that dropped an inch or more of snow on the Washington area, snarling traffic and triggering countless fender-bending accidents. By nightfall, the mercury had reached 39 and most of the snow had melted, letting homebound traffic move normally.

Yesterday's snowfall revived memories among longtime Washingtonians of the infamous storm that unexpectedly dropped eight inches of snow on the capital city on the eve and early morning of John F. Kennedy's inaugural in January 1961.

Homebound commuters took eight hours or more in some cases then to get to the outer suburbs. Hundreds of stalled cars were towed off arterials and parked on the Ellipse and the Mall. Army troops were called in to help clear Pennsylvania Avenue so the Kennedy inaugural parade could take place on schedule.

That was the second worst inaugural snowstorm on record. The worst was when William Howard Taft took office in 1909, when 9.8 inches of snow was on the ground. Taft's inaugural occurred on March 4 -- the date originally set by the Constitution and altered by an amendment that took effect in 1937.

By those standards, yesterday's pre-inaugural storm was tame -- caused by a weak low-pressure system that moved in from the Ohio River valley and, after dusting Washington, drifted southward. It dropped one inch on National and Dulles airports and up to two inches in some parts of the region.

The snow began about 4:45 a.m. in Washington, with the temperature hovering just below the freezing mark, and early rush-hour travelers found streets and roads treacherously slick. The D.C. Department of Transportation, heeding warnings from the weather service and from its own private forecasting consultant, dispatched about 40 trucks that spread sand and salt, chiefly on bridges and overpasses.

The worst traffic snarls were reported in Fairfax County, where a tractor-trailer hauling fuel oil jackknifed on I-66 just west of Capital Beltway, and five cars piled up near Lorton on I-95. The truck tank ruptred, spilling 8,000 gallons and leading police to detour traffic in both directions off the freeway.

Police also closed the Beltway for an hour and a half at midday near Route 7 after power lines caught fire because of a short circuit.

Virginia state police recorded more than 100 accidents, most of them minor and one involving a state police vehicle. One car on the George Washington Memorial Parkway near McLean spun out of control and hung precariously over the edge of a steep embankment. In Prince George's County, state police reported a car occupied by a woman and two children overturned on the Capital Beltway near Branch Avenue, but no one was hurt seriously.

Bad weather on Inaugration Day is a celebrated tradition of American political fokelore, according to Patrick Hughes of the National Oceanic and Atmospheric Administration, parent organization of the Weather Service, who wrote an article on the subject for a magazine called Weatherwise.

The weather was good for the first seven inaugurals, all held indoors, but turned sour after they were moved outdoors. Of the 41 regularly scheduled inaugurals that followed, Hughes found that 19 were plagued by rain, snow, sleet or bitter cold.

The coldest inauguration on record was in 1873, when Ulysses S. Grant took the oath for his second term with the temperature four degrees above zero and the wind blowing at up to 40 miles an hour. The wettest was Franklin D. Roosevelt's second inauguration in 1937 (which was the first one held on a Jan. 20) when the windblown rain fell in slanting sheets with the temperature just above freezing.