Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 162 | 153 | 176 | 175 | 182 | 171 |
| Tmin | 164 | 140 | 167 | 165 | 178 | 173 |
| Duration of sunshine | 182 | 155 | 178 | 174 | 183 | 174 |
| Precipitation | 186 | 166 | 190 | 183 | 188 | 180 |
| Humidity/Visibility | 184 | 164 | 183 | 178 | 184 | 178 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 176 | 156 | 161 | 139 | 137 | 117 |
| Tmin | 176 | 155 | 163 | 147 | 134 | 113 |
| Duration of sunshine | 182 | 158 | 151 | 148 | 144 | 123 |
| Precipitation | 186 | 190 | 214 | 229 | 216 | 221 |
| Humidity/Visibility | 183 | 184 | 205 | 205 | 204 | 213 |
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. |
