Poul la Cour was born on the farm Skærsø in 1846 on Djursland, where his father was a spiritual and technical guard farm owner. In high school la Cour wanted to become a priest, but a poor grade in Greek and an A+ in mathematics indicated that his talents lay elsewhere.
His brother J.C. la Cour, who later became president of the Agricultural Society, advised him to study science and become a meteorologist. In 1869, he took his examination for a Master of Science degree in meteorology, a new field of study at the time. He was awarded a silver medal for his thesis on the height of connecting cloud layers.
When the Meteorological Institute was established in 1872, Poul la Cour became the deputy director. One of his functions was to establish weather stations around the country.
In 1878, he started as a teacher at Askov Folk High School and began a completely new life. He became an initiator, inventor folk high school teacher, and was deeply involved in improving social conditions. Before he died in 1908, la Cour had been a great influence on many aspects of Danish society.