Retail sales in the metrpolitan Washington area rose 12 percent in 1980 to a record $15.28 billion conpared with $13.6 billion in 1979, the Commerce Department reported last week.

Although area sales rose gradually throughout the year and topped $1 billion in every month during the year, a sharp increase in holiday shopping during December capped of the year with monthly sales of $1.6 billion. That total was up 24 percent from November. The apparent last-minute Christmas sales rush helped the local retail industry, but results for the full year were disappointing for general merchandise retailers, such as department stores.

The Commerce Department figures show that general merchandise sales, while up 57 percent in December from a lackluster November, rose just 8 percent for the full year. Nondurable goods sales, including food, increased 18 percent for the year as inflation boosted grocery store prices some 13 percent.

Overall retail sales figures include general retailers, food stores, automobile dealers and restaurants.

Nationwide during 1980, overall retail sales rose just 7 percent compared with the 12 percent gain in the D.C. area. Nationwide durable goods sales were off 3 percent, auto sales fell 6 percent, department store sales increased 6 percent and nondurable goods volume rose 11 percent, reflecting food hikes.

In the department store sector alone, Washington retailers reported sales of $260 million during December, up only 6 percent from a year earlier but 52 percent above the level in November. For the year, area department store sales were up 5 percent from 1979 at $1.68 billion.

Downtown Washington department store sales totaled $14.8 million in December, unchanged from a year ago but 49 percent higher than in the previous month. Sales at the bid D.C. stores for all of 1980 rose 4 percent to $107 million, the government reported.

In downtown Baltimore, department store sales in December were $4.4 million, a gain of 2 percent from 1979. For the year, however, downtown Baltimore sales declined 3 percent to $30.5 million.

All retailers in metropolitan Baltimore reported sales in December of $1.02 billion, an increase of 12 percent from a year ago. Overall Baltimore area retail sales last year were up 9 percent to $9.17 billion.

Among metropoliltan areas in Virginia, department store sales last year were up 5 percent to $312 million in Richmond; up 9 percent to $311 million in Norfolk-Virginia Beach-Portsmouth; up 3 percent to $167 million in Newport News-Hampton; up 2 percent to $107 million in Roanoke and up 9 percent to $62 million in Lynchburg.