Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 277 | 250 | 279 | 280 | 298 | 292 |
| Tmin | 278 | 250 | 279 | 286 | 300 | 285 |
| Duration of sunshine | 217 | 226 | 217 | 180 | 310 | 270 |
| Precipitation | 93 | 85 | 95 | 111 | 124 | 122 |
| Humidity/Visibility | 91 | 84 | 92 | 104 | 123 | 119 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 291 | 288 | 274 | 302 | 297 | 303 |
| Tmin | 304 | 299 | 273 | 303 | 299 | 310 |
| Duration of sunshine | 310 | 279 | 270 | 248 | 240 | 279 |
| Precipitation | 127 | 127 | 120 | 124 | 120 | 125 |
| Humidity/Visibility | 122 | 121 | 118 | 117 | 117 | 123 |
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. |
