For the comfort of the shivering multitudes in Monday's inaugural parade, 62 tents equipped with portable heaters will be erected on and around the Mall, the assembly point for the procession.

Spectators lining the parade route are on their own.

True to inaugural tradition, the weather Monday is expected to be decidedly less than ideal: Not the worst possible scenario (a freak blizzard, a driving rain) but not the benevolent best either.

In its latest inaugural forecast, the National Weather Service is predicting fair skies and frigid temperatures, including an afternoon high of only 25 degrees.

"It'll be a day for the hardy," said Col. Greg Gagne, a spokesman for the Armed Forces Inaugural Committee. "You might say those who come out will be the true patriots."

For now, forecasters don't expect a repeat of the four inches of snow dumped on the Washington area yesterday. That, however, is always subject to change.

For, as inaugural coordinators well know, they can plan the most exacting details of the 50th Presidential Inauguration, but they can't plan the weather.

"If people ask what would be the biggest foul-up, it's always, always the weather," said Sherrie Sandy, a spokeswoman with the Presidential Inaugural Committee.

Only under the most severe conditions -- for example, a blinding downpour -- would President Reagan take the oath of office in the Capitol rotunda rather than from the platform outside. Likewise, the parade would be cancelled only under the most extreme circumstances, Sandy said; so far, that has never happened. In case of a cancellation, the parade would not be rescheduled.

Four years ago, inaugural planners had few worries. The weather was relatively spring-like with an afternoon high of 56 degrees.

Other inaugurations have not been so fortunate. On nearly half the presidential inaugural days since 1937, there has been rain, snow or numbing cold. The 20th Amendment changed the inauguration date from March 4 to Jan. 20.

As it happened, President Franklin Roosevelt's second inauguration on Jan. 20, 1937 -- the first inauguration under the new date -- was nearly washed away by the heaviest rain in the event's history. Refusing to take the oath indoors, Roosevelt placed his right hand on a cellophane-wrapped Bible while cold rain whipped at his face.

In more recent years, the most uncooperative weather accompanied President John F. Kennedy's 1961 inauguration. The day before Kennedy took office, the worst snowstorm in inauguration history brought eight inches of snow to Washington. Nevertheless, snowplows droned throughout the night to clear the parade route and an estimated 1 million spectators braved 22-degree temperatures and a stinging 19-mph northwest wind to watch the procession go by.

Throughout history, a number of other presidents have faced similar trials on their important day. The sound of rain drumming on spectators' umbrellas drowned out the words of James K. Polk's inaugural address in 1845.

Ulysses S. Grant shivered through the coldest inauguration on record (16 degrees) in 1872. And William Howard Taft, surveying the polar landscape that greeted his Inaugural Day in 1909, reportedly joked, "I always knew it would be a cold day when I got to be president."

But the chief executive who undoubtedly fared the worst because of inaugural weather was William Henry Harrison in 1841.

Harrison, who was 68, flitted through the raw, windy day without a hat or an overcoat. Although he promptly developed a cold, Harrison continued to ignore his health. The cold deepened into pneumonia, he slipped into a coma, and Harrison died on April 4, one month to the day after he became president.