With solitary-living species, such as the European roe deer (Capreolus capreolus), high individuality is also expected to influence activity. Here we studied the annual activity patterns of European roe deer in the Bavarian Forest National Park. We investigated the influence of age and sex, the weather, and the individuality. We used sex-specific generalized additive models with variables that considered the age of the animal and also the high-resolution site-specific parameters temperature, precipitation, and snow depth. Data from 20 males and 9 females were gathered continuously with GPS-GSM collars carrying a dual-axis acceleration sensor. Our results indicated that the main factors influencing the activity patterns of the crepuscular roe deer in the Bavarian Forest National Park are the individual, the season, and the time of day, and that weather parameters are secondary. GPS-GSM collars with a dual-axis acceleration sensor allow long-term, continuous, and remote activity monitoring of European roe deer.