Wilhelm Friedrich Nesemann (also Neseman) was the son of Friedrich Wilhelm Nesemann and his wife Wilhelmina E. Kraemer. He was born in what was then Prussia, but his birthplace is now in the Czech Republic. He emigrated to South Africa, became a merchant, and in April 1877 married Francis Sophia Hadlow in Uitenhage. Although they had five children only two survived, including their son Alfred Nesemann*who became a nature lover like his father. Nesemann and his family resided at Burgersdorp in 1878, but by 1879 had settled in Steynsburg, Eastern Cape, where he established a business in 1881 and remained for most of the rest of his life. By 1903 he held the position of town clerk. In 1905 he became the secretary of the Colonial Trust Corporation, Ltd. in Graaff-Reinet. He was a versatile person, who's interests included music and watchmaking.
From the beginning of 1889 Neseman made regular meteorological observations for the Cape of Good Hope Meteorological Commission, a summary of which was published annually in the Commission's Report. In 1897 his station was upgraded to a second order meteorological station, and from 1899 he also managed an evaporation station, of which there were only seven in the colony at that time. His observations continued to the end of 1905, when his station was closed.