This dataset provides chironomid count data for core tops from 20 lakes located near Bergen, Norway. The lakes are situated either in the Røldal region or in the Førde region. For each lake, the chironomid counts as well as the coordinates (latitude/longitude) are presented. We obtained samples from the centre of each lake using a HON/Kajak gravity corer and analysed the top-centimetre (0-1 cm sediment depth) to determine the composition of the chironomid fauna. All sediment samples were retrieved during fieldwork in August and September 2019. Samples were transported to the laboratory (Birkbeck University of London, UK), where they were weighted and processed using standard protocols – this involved 20 min treatment with warm KOH (10 %) and sieving over a 100 µm mesh. Chironomid head capsules were subsequently handpicked from the residue, mounted on permanent microscope slides, and identified using Brooks et al. (2007). This dataset provides chironomid count data in number of chironomid head capsules per sample. Through a comparison against data from 1996 (Brooks & Birks, 2001), the chironomid dataset provides insight in the recent changes in the insect community of the lake ecosystem under ongoing climate change.