The weather-forced cancellations of President Reagan's public swearing-in ceremony and inaugural parade have meant changes in some other inaugural day arrangements. Present plans include:

11:30 a.m.: President Reagan will take the oath of office in a private Capitol rotunda ceremony witnessed only by members of Congress, the Cabinet and other dignitaries. His inaugural address will be televised.

3 p.m.: An alternative event will be held at the Capital Centre for the estimated 12,000 people who came here to participate in the parade.

8 p.m.: Presidential inaugural balls: Pension Building, Washington Convention Center (two balls), Washington Hilton, Sheraton Washington Hotel, Air and Space Museum, Kennedy Center and Shoreham Hotel. Inauguration Ball for Young Americans: D.C. Armory.

Street Closings: Except for the Capitol Hill area, previously announced street closings and parking restrictions are no longer in effect.

Parking and Traffic: Weekday regulations will be lifted.

Metro: Subways will still operate later than usual, from 6:30 a.m. today to 1:30 a.m. tomorrow, although Metro officials say they will be using fewer cars. Metrobuses will operate on a Saturday schedule.

Other Events: All previously announced indoor inaugural-related activities are expected to be held as scheduled, according to inaugural officials. Members of the public, however, are advised to call ahead as a precaution against cancellation.

Ticket Refunds: The inaugural committee says it is still working out the details but expects to make refunds by Feb. 10 to about 25,000 people who purchased seats along the parade route.