Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 913 | 830 | 920 | 890 | 917 | 891 |
| Tmin | 955 | 858 | 955 | 919 | 954 | 923 |
| Duration of sunshine | 260 | 236 | 293 | 282 | 296 | 284 |
| Precipitation | 192 | 176 | 194 | 189 | 194 | 186 |
| Humidity/Visibility | 177 | 161 | 180 | 171 | 180 | 173 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 926 | 922 | 919 | 947 | 912 | 942 |
| Tmin | 955 | 960 | 958 | 981 | 950 | 981 |
| Duration of sunshine | 283 | 291 | 317 | 321 | 306 | 318 |
| Precipitation | 188 | 194 | 216 | 217 | 212 | 229 |
| Humidity/Visibility | 181 | 182 | 200 | 206 | 201 | 206 |
Climate data is usually derived from meteorological data of a certain number of years. The actual number of recorded years may vary from only a couple to 50 years or more. The quality of climate data depends on the number of available recorded years. Fewer years means less reliable data. The standart-period for reliable climate data is 30 years. For example, the mean monthly temperature for, let's say January, would ideally calculated from a total number of 930 recorded January-days. However, the usual number of recorded days is much smaller. The table above shows the actual number of recorded days for every parameter measured. |
