Common summer visitor and passage migrant.

Swifts are dependent on old buildings for nesting. Modern building design, materials and regulations are reducing potential nest sites.

They generally arrive in Stevenage during the first week of May and depart again during the first ten days of August. The earliest spring arrival date is 21 April 2018 when three were seen at Fairlands Valley Park, the latest departure date is 7 November 1982.

They are regularly seen in the High Street particularly around Holy Trinity Church. Up to 80 were seen at Sish Lane between 17 and 20 July 1976, 30 were seen over the Old Town on 24 July 2014, 50 over the Old Town on 28 July 2016 and 50 over the Old Town on 27 July 2023.

The largest numbers seen are: 100 plus flying low over fields near Boxfield Cottage (now Chells Manor) on 18 July 1976; 100 plus seen for at least three hours over Watery Grove on 23 July 1978; 60 at Popple Way on 12 August 1978; 400 at Fairlands Valley Lakes on 6 July 1980; 60 at Norton Green Tip on 3 August 2014; 100 plus at Fairlands Valley Lakes on 6 June 2023.

The 1973 Breeding Atlas confirmed breeding from six tetrads covering Stevenage, the 1992 Atlas confirmed breeding from five tetrads and the 2012 Atlas confirmed breeding from two tetrads.

In 2018 nesting was reported from Stevenage. In 2020 birds were seen visiting a nest site in Pin Green and in 2021 two were seen entering eaves in Stanley Road.

In 2023 nesting was recorded from Basils Road (two nests including one on the Bunyan Baptist Church), Greydells Road (one nest), Haycroft Road (four nests), Julians Road (one nest), Lawrence Avenue (two nests), Lister Hospital (two nests), Stanley Road (one nest) and, Whitesmead Road (one nest).