Data comprise monthly ammonia air concentrations from UK CEH ALPHA® (Adapted Low-cost Passive High Absorption) samplers co-located with UKEAP DELTA sites for the period of time from January 2021 to December 2021. The UK Eutrophying and Acidifying atmospheric Pollutants (UKEAP) network measures air pollutants at rural sites across the UK. Originally the purpose of these measurements was for a calibrated ALPHA® uptake rate for the UK CEH Edinburgh research laboratory. Samplers are exposed in monthly cycles at the beginning of each month. Full details about this dataset can be found at https://doi.org/10.5285/ab6e6c87-0433-4b13-bf6c-24c81359cde3
