VDI 3786 Blatt 9:2007-10 (R2017)

The results of visual weather observations contain individual, subjective errors and may strongly deviate from each other in a particular case. In order to make the results nevertheless comparable, i.e. to keep subjective influence as low as possible, strict regulations for the observation and the recording are necessary. On this subject, the weather services have developed a comprehensive system. The guideline is based on this system.