Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 84 | 66 | 54 | 88 | 107 | 99 |
| Tmin | 82 | 67 | 52 | 94 | 116 | 111 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 111 | 90 | 91 | 131 | 136 | 144 |
| Humidity/Visibility | 86 | 77 | 78 | 102 | 113 | 109 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 99 | 101 | 101 | 105 | 102 | 109 |
| Tmin | 112 | 118 | 112 | 106 | 106 | 109 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 137 | 138 | 134 | 130 | 148 | 150 |
| Humidity/Visibility | 111 | 114 | 110 | 113 | 107 | 115 |
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. |
Al-Jizah