Lesser Whitethroats breed in Europe, except in Iceland, northern Fenno-Scandia and Russia, Ireland, west and southwest France, Spain and almost all of Italy. From Europe their range extends through Turkey and the Middle East to east-central Siberia, Mongolia and western China. They winter in sub-Saharan Africa, mainly in the northeast, but also in Chad, Niger, Mali and Senegal.
    In Britain their breeding area is concentrated mainly in the south and east of England. They also breed in lowland areas near coasts in southwest England, Wales, northern England and southern Scotland. They are largely absent from upland areas and the whole of northern Scotland. They are however extending their range northwards: Bird Atlas 2007-2011 recorded a 32% increase in their distribution since the 1968-72 Breeding Atlas, mostly in the north. This was against a background of a stable population from the 1960s to the late 1980s, a moderate decline during the 1990s and an increase since then.
    National records show regular fluctuations from year to year in the numbers of Lesser Whitethroats arriving in Britain, a pattern that has also been apparent in Wiltshire records, varying from the mid-19th century ("quite common") to the early 20th ("less numerous"), mid-20th ("fairly common") and in the 1980s "numbers fluctuate widely from year to year".  Birds of Wiltshire recorded them in 374 tetrads with breeding in 154. WTA2 recorded them in only 318 tetrads, with breeding in 85.
       
References
The following references are used throughout these species’ accounts, in the abbreviated form given in quotation marks:
1968-72 Breeding Atlas” – Sharrack, J.T.R. 1976:  The Atlas of Breeding Birds in Britain and Ireland. T. & A. Poyser
1981-84 Winter Atlas” – Lack, P.C. 1986:  The Atlas of Wintering Birds in Britain and Ireland. T. & A. Poyser
1988-91 Breeding Atlas” – Gibbons, D.W., Reid, J.B. & Chapman, R.A. 1993: The New Atlas of Breeding Birds in Britain and Ireland 1988-91. T. & A. Poyser
Birds of Wiltshire” – Ferguson-Lees, I.J. et al. 2007: Birds of Wiltshire, published by the tetrad atlas group of the Wiltshire Ornithological Society after mapping fieldwork 1995-2000. Wiltshire Ornithological Society.
Bird Atlas 2007-2011”-– Balmer, D.E., Gillings, S., Caffrey, B.J., Swann, R.L., Downie, I.S. and Fuller, R.J. 2013: The Breeding and Wintering Birds of Britain and Ireland. BTO Books. 
WTA2” – ("Wiltshire Tetrad Atlas 2 ") the present electronic publication, bringing together the Wiltshire data from “Birds of Wiltshire” and “Bird Atlas 2007-11”, together with data from further fieldwork carried out in 2011 and 2012.
"Hobby" - the annual bird report of the Wiltshire Ornithological Society.