Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 1126 | 1036 | 1149 | 1090 | 1081 | 1068 |
| Tmin | 1104 | 1035 | 1131 | 1082 | 1084 | 1058 |
| Duration of sunshine | 114 | 125 | 124 | 135 | 142 | 138 |
| Precipitation | 183 | 168 | 187 | 175 | 158 | 180 |
| Humidity/Visibility | 145 | 144 | 158 | 150 | 144 | 154 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 1138 | 1161 | 1137 | 1169 | 1116 | 1151 |
| Tmin | 1120 | 1154 | 1123 | 1161 | 1108 | 1139 |
| Duration of sunshine | 136 | 145 | 150 | 152 | 163 | 155 |
| Precipitation | 188 | 191 | 212 | 214 | 210 | 193 |
| Humidity/Visibility | 157 | 153 | 169 | 173 | 176 | 165 |
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. |
