Abstract Estimates of diurnal and seasonal variation of ozone deposition to a temperate coniferous forest over 3 years in Southern Norway are presented. The estimates are based on the gradient method. Ozone deposition velocities are also produced by the EMEP deposition module for the same site with measured local meteorology as input. There is relatively good correspondence for diurnal cycles for all four seasons, suggesting that the module is able to provide characteristic results for this site. However, there are some discrepancies in the diurnal peak velocities, particularly in summer. Annual average deposition velocity estimated by the gradient method is 1.8 mms −1 while the corresponding value calculated by the deposition module is 2.1 mms −1.