Alfred H. Thiessen (born April 8, 1872, died 1956) was an American meteorologist after whom Thiessen polygons are named.

Alfred H. Thiessen was born in Troy

Troy, New York

Troy is a city in the US State of New York and the seat of Rensselaer County. Troy is located on the western edge of Rensselaer County and on the eastern bank of the Hudson River. Troy has close ties to the nearby cities of Albany and Schenectady, forming a region popularly called the Capital...

, New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

. He earned a BS from Cornell University

Cornell University

Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...

 in 1898. His service in the Weather Bureau (today NOAA - the National Oceanic and Atmospheric Administration) began at Pittsburgh as observer on July 1, 1898. He subsequently was assigned to Helena, Washington, Point Reyes and Manteo as assistant, and to Mount Weather, Raleigh, Indianapolis, Salt Lake City, Portland, Baltimore, and Denver as official in charge. He resigned from the Weather Bureau on December 11, 1920 to accept a commission as Captain in the Regular Army. He left active service, as a Major, and was reappointed at the Central Office of the Weather Bureau on March 17, 1941. He retired on April 30, 1942.

His best known work (1911) dealt with the description of weather prediction with a geometric method for dividing land areas, that although known from Dirichlet Tessellation (1850) and the Voronoi Diagram (1908), apparently had never been used in meteorology for interpolation of measurements. The synonyms Thiessen polygons or Thiessen method have become established for this application.

Thiessen polygons have also been used to estimate the areas of influence of Mayan

Maya civilization

The Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as for its art, architecture, and mathematical and astronomical systems. Initially established during the Pre-Classic period The Maya is a Mesoamerican...

city-states.