Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 48 | 47 | 49 | 48 | 58 | 59 |
| Tmin | 57 | 53 | 55 | 53 | 63 | 71 |
| Duration of sunshine | 41 | 32 | 41 | 42 | 47 | 57 |
| Precipitation | 74 | 65 | 66 | 76 | 84 | 94 |
| Humidity/Visibility | 39 | 38 | 40 | 40 | 46 | 50 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 73 | 81 | 72 | 61 | 69 | 68 |
| Tmin | 70 | 84 | 75 | 75 | 73 | 66 |
| Duration of sunshine | 61 | 69 | 61 | 52 | 38 | 40 |
| Precipitation | 104 | 109 | 102 | 96 | 109 | 123 |
| Humidity/Visibility | 58 | 63 | 58 | 53 | 52 | 52 |
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. |
