Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1082 | 980 | 1084 | 1050 | 1084 | 1066 |
| Tmin | 1085 | 976 | 1084 | 1049 | 1084 | 1066 |
| Duration of sunshine | 155 | 135 | 153 | 149 | 154 | 166 |
| Precipitation | 155 | 140 | 155 | 150 | 155 | 168 |
| Humidity/Visibility | 154 | 138 | 154 | 149 | 154 | 166 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1111 | 1113 | 1079 | 1108 | 1077 | 1115 |
| Tmin | 1111 | 1116 | 1080 | 1110 | 1079 | 1116 |
| Duration of sunshine | 179 | 186 | 180 | 178 | 179 | 184 |
| Precipitation | 186 | 190 | 210 | 217 | 209 | 219 |
| Humidity/Visibility | 180 | 186 | 207 | 210 | 206 | 215 |
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. |
