The dingy skipper is associated with birds-foot trefoil and can be found in quarries, on open rough ground, edges of woodland, even on heathland; it is particularly on chalk and limestone.
Dingy Skipper: unfairly accused
Dingy Skipper in Dorset: what your tweets tell us ...
The dingy skipper can be mistaken for one of the similar day flying moths as it not only resembles species like the Burnett companion it flies and behaves like them too. Once settled identification is easier but the dingy skipper is a very active butterfly, especially on warm days, and finding one at rest can be difficult. Widespread and fairly common in Dorset but perhaps infrequent is a better description? The dingy skipper can be found where common bird's-foot trefoil occurs which its larval food plant. As bird's-foot trefoil is quite common it means the dingy skipper may be encountered on chalk grasslands, heath, coastal dunes, even woodland glades, but sunny downland slopes are where the majority are found.
The dingy skipper flies from late April until the end of June and there may be a second brood in good years. That is reflected in the weekly reports chart with the earliest record we have being from week 17 right at the end of April and then reports are weekly until week 23, about the third week in June. There are then reports from week 31 to 33 in August, three reports in 2017 but just one in 2018.
So far there are reports from 29 different sites with Ballard Down, Durlston Country Park and Giant Hill producing the most. The distribution map shows sites along the Purbeck Ridge, the Purbeck Coast, Portland, the South Dorset Ridgeway and the downland spine running through the county from roughly Bridport to Shaftesbury; this emphasises, I think, the preference for calcareous soils and certainly bird's-foot trefoil thrives in these conditions. A walk on Ballard Down starting from Ulwell in late May/early June should produce a dingy skipper sighting for you.