A city-wide celebration of Mexican arts has been organized to complement the major exhibition, "Mexico: Splendors of 30 Centuries," at the Metropolitan Museum of Art through Jan. 13, 1991.

The Metropolitan's show features some 400 works from the pre-Columbian era through the 20th century drawn from collections in Mexico, Europe and the United States. After its showing here, it will be shown at the San Antonio Museum of Art, April 6-Aug. 4, 1991, and the Los Angeles County Museum of Art, Sept. 12-Dec. 29, 1991.Related activities feature Mexican art, photography, literature, poetry, music, theater, dance, cinema, cuisine, fashion and festivals. Some 50 New York cultural institutions, in addition to the Metropolitan, have planned exhibitions, performances, workshops and seminars through January 1991.

Among events are "Between Worlds: Contemporary Mexican Photography," Nov. 16-Feb. 3, 1991, at the International Center of Photography and a visual appetizer in "Pre-Hispanic Foods of Mexico," a photo exhibition at the American Museum of Natural History.