Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 388 | 345 | 364 | 396 | 415 | 402 |
| Tmin | 393 | 344 | 363 | 396 | 424 | 412 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 359 | 321 | 348 | 370 | 390 | 380 |
| Humidity/Visibility | 85 | 73 | 80 | 105 | 114 | 112 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 408 | 410 | 406 | 420 | 404 | 420 |
| Tmin | 424 | 423 | 410 | 420 | 406 | 421 |
| Duration of sunshine | 0 | 0 | 0 | 0 | 0 | 0 |
| Precipitation | 390 | 390 | 376 | 378 | 390 | 396 |
| Humidity/Visibility | 113 | 111 | 111 | 114 | 109 | 117 |
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