Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 165 | 159 | 179 | 164 | 174 | 170 |
| Tmin | 177 | 162 | 182 | 176 | 183 | 169 |
| Duration of sunshine | 176 | 158 | 173 | 172 | 172 | 162 |
| Precipitation | 192 | 173 | 188 | 181 | 190 | 182 |
| Humidity/Visibility | 128 | 113 | 132 | 118 | 123 | 118 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 168 | 161 | 194 | 198 | 169 | 200 |
| Tmin | 176 | 175 | 200 | 204 | 195 | 206 |
| Duration of sunshine | 164 | 172 | 181 | 185 | 161 | 167 |
| Precipitation | 185 | 196 | 220 | 232 | 210 | 225 |
| Humidity/Visibility | 116 | 114 | 136 | 150 | 141 | 152 |
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. |
