This data set contains measurements of ancillary environmental variables recorded half-hourly at each flux chamber or chamber site. Each chamber had three individual temperature sensors (IKES-50-6.0-5M PT100, Nokeval, Finland) tracking the temperature inside the chamber as well as in 2 cm and 10 cm soil depth. At the bog site, a temperature profile with 5 depths down to 95 cm was established as well. Each microsite uses a soil moisture sensor (ML3-UM-2.1, Delta-T devices Ltd, UK) to track the volumetric water content of the upper 10 cm soil depth. The wet bog microsite was regularly waterlogged and therefore soil moisture was replaced with water table depth (WTD) measurements. Photosynthetically active radiation (PAR) was measured per microsite with sensor PQS1 (Kipp & Zonen, Netherlands). The dry bog and forest microsite PAR both have limited relevance for the individual chamber due to inconsistent shading of the surrounding trees but rather represent PAR for the microsite in general. The environmental data was collected to characterize site conditions and their changes over the year and to identify environmental drivers of CO2, CH4, and N2O fluxes along the moisture gradient.