| Month | Total organic carbon (g/kg) | |
| King Fahd station | Airport station | |
| January | 0.211 | 0.054 |
| February | 0.345 | 0.184 |
| March | 0.395 | 0.127 |
| April | 0.315 | 0.131 |
| May | 0.467 | 0.342 |
| June | 0.506 | 0.103 |
| July | 0.201 | 0.102 |
| August | 0.287 | 0.156 |
| Total | 2.730 | 1.20 |
| Average | 0.340 | 0.150 |