Helmut E. Landsberg, 79, a professor emeritus and former director of the meteorology department at the University of Maryland, died Dec. 6 at a hotel in Geneva after a heart attack. He was in Switzerland on a business trip.

Dr. Landsberg, who was a resident of Temple Hills, was born in Frankfurt, Germany. He graduated from the University of Frankfurt, where he also earned a doctorate in meteorology. He moved to this country in 1934 and settled in Pennsylvania. He taught at Pennsylvania State University and the University of Chicago before moving here in 1943.

For the next three years he was a weather consultant to the Army Air Forces. He joined the old U.S. Weather Bureau in 1946, and was its climatology director from 1956 to 1965.

Dr. Landsberg joined the faculty at the University of Maryland as a research professor in 1966. He was a former director of the university's institute for fluid dynamics and applied mathematics and was director of the meteorology department when he retired in 1976, as a professor emeritus.

He was presented the National Medal of Science by President Reagan in 1984. He also received the American Meteorological Award for his achievements in bioclimatology.

Dr. Landsberg was a member of the National Academy of Engineering, the American Association of State Climatologists, and the Royal Meteorological Society.

Survivors include his wife, A. Frances Landsberg of Temple Hills; a son, Bruce, of Wichita, Kan., and three grandsons.