These data include all avalanches that were mapped in the region of Davos, Switzerland during the winters 1998-1999 to 2018-2019 (21 years), in total 13,918 avalanches, and the corresponding forecast danger level valid on the day of avalanche occurrence, 3533 days and danger ratings in total. This avalanche activity data set was analysed and results published by Schweizer et al. (2020). They found that the number of avalanches per day strongly increased with increasing danger level, but avalanche size was poorly related to avalanche danger level. The data are provided in two files: the first includes the avalanche data (13,918 records); the second includes the avalanche activity per day (3533 records). Please refer to the Read-me file for further details on the data. These data are the basis of the following publication: Schweizer, J., Mitterer, C., Techel, F., Stoffel, A. and Reuter, B., 2020. On the relation between avalanche occurrence and avalanche danger level. The Cryosphere, 14, 737-750, https://doi.org/10.5194/tc-14-737-2020.