On 4 August 1886 How married Katharine Hutchinson, daughter of the Rev. William Hutchinson, vicar of Blurton. The couple had three sons and one daughter. The sons were:
William Henry Walsham How (born 1887), cleric
Douglas Walsham How (1889–1942), official in Basutoland
Robert Walsham How (born 1891)
Their daughter Rachel Walsham How (born 1887) married in 1915 the Rev. William Prescott-Decie (1867–1927).
↑ECCLESIASTICAL INTELLIGENCE The Hampshire Advertiser (Southampton, England), Saturday, 25 July 1885; pg. 2; Issue 4081
↑INSTITUTION OF THE NEW VICAR OF MIRFIELD. The Huddersfield Chronicle and West Yorkshire Advertiser (West Yorkshire, England), Saturday, 9 March 1889; pg. 7; Issue 6740