Constable was fascinated with the volatility of nature. In this work  he painted billowy cumulus clouds in a sky that takes up two thirds  of the picture. He emphasised the fresh breeze and changeable weather conditions through the tilting forms of the small sailing boats in the middle distance. He lit up the lower portion of the picture by painting a streak of sunlight across the sea, in contrast to the remainder of the foreground in shadow.

Constable painted at least three versions of this subject (this version; one in the Yale Center for British Art, New Haven; and one in a private collection) based on a pencil sketch drawn around 1815, to which he added the clouds and extended the scene to the left. He had studied the low horizon line in the seascapes by Willem van de Velde displayed at the British Institution in the summer of 1819, and may have used these observations (R 19.18A and 19.18B) when working on his Harwich Lighthouse paintings. In 1820 he exhibited one of his paintings of this subject at the Royal Academy. A critic noted that the interest in this work ‘arises from its truth and locality’ (The Literary Gazette, 6 May 1820, cit. Ivy 1991, p. 84) and compared it to paintings by the seventeenth-century Dutch artists Ruisdael and Hobbema. Another commented that Constable had achieved ‘a more exact look of Nature than any picture we have ever seen by an Englishman’, in his Stratford Mill 1819–20, and that ‘His cabinet picture of Harwich Lighthouse has the same capital character’ (The Examiner, 15 May 1820, cit. Ivy 1991, pp. 84–85).

When Constable sketched the lighthouse, known as the low lighthouse, it was a wooden structure – to be replaced by a different construction in 1817–18. It was leased at the time by Constable’s patron and friend Major-General Slater-Rebow of Wivenhoe Park, who was responsible for its upkeep. In 1816 Slater-Rebow offered Constable two commissions, ‘The Quarters’ behind Alresford Hall   and Wivenhoe Park, Essex (National Gallery of Art, Washington), but he is not known to have had direct involvement with any of Constable’s paintings of Harwich Lighthouse. 

This composition recalls seventeenth-century Dutch coastal views and indicates the way in which Constable looked to the work of earlier artists while creating his own unique vision. Such small-scale cabinet pictures  in the Dutch manner were popular with collectors.

Reynolds notes that the skies are similar in the three known versions of Harwich Lighthouse, and Constable used similar skies in his Yarmouth Jetty compositions of 1822–23, and that this is contrary to his usual practice of changing his skies in his variations on a subject.