Despite the pandemic and lockdown disruptions, many groups were able to monitor substantial numbers of Barn Owl nests and collectively contribute to a reliable impression of the 2020 breeding period. 
You can read the results, presented here in the State of the UK Barn Owl Population 2020, were poor in general, particularly in terms of mean brood size.
Although three projects from the northern region reported positive outcomes, results were mixed from the Midwest, disappointing from the eastern seaboard, and were even worse from central England, South Wales, and the southwest. It may be no coincidence that the second poorest mean brood size in the history of the State of the UK Barn Owl Population reports has occurred during a year when rainfall swung from unusually dry to very wet, and right at the time when eggs needed incubating and owlets should have been growing.
Compiled by the Trust and published in April 2021 the 2020 contributors were:
Barn Owl Trust
Brandon Ringing Group
Broxton Barn Owl Group
Bucks Owl & Raptor Group
Derbyshire Ornithological Society
East Cleveland Nest Box Network Project
East Riding Barn Owl Conservation Group
Garry Steele
Glamorgan Barn Owl Group
Gloucestershire Raptor Monitoring Group
Lewis Raptor & Owl Group
Manchester Raptor Group
Middle Thames Ringing Group
North Dorset – Conservation Action
North West Norfolk Ringing Group
Philip Hanmer – Nat. Hist. Soc. of Northumbria Hancock Mus. R.G.
Powys – Species Habitat Protection Group
Scottish Raptor Study Group
Shropshire Barn Owl Group
Staffordshire Barn Owl Action Group
Stour Valley Wildlife Action Group
Suffolk Community Barn Owl Project
Sussex Ornithological Society – Barrie Watson
Sussex Ornithological Society – Graham Roberts
Thornham Owl Project
Ulster Wildlife
Vale of Belvoir Barn Owl Conservation Group
West Berkshire Countryside Society Barn Owl Group
West Cornwall Ringing Group