Table 2.
The climate data of Mehrabad national airport, Tehran, Iran.
| Month | Air T (°C) | Earth T (°C) | Relative humidity | Daily solar radiation – horizontal (kWh/m2/d) | Atmospheric pressure (kPa) | Wind speed (m/s) |
|---|---|---|---|---|---|---|
| Jan. | 3.0 | 1.0 | 60.1% | 2.44 | 88.5 | 35 |
| Feb. | 5.3 | 2.5 | 51.6% | 3.33 | 88.3 | 50 |
| Mar. | 10.3 | 7.3 | 46.4% | 4.08 | 87.9 | 64 |
| Apr. | 16.4 | 15.7 | 41.6% | 5.42 | 87.5 | 71 |
| May | 22.1 | 21.9 | 34.2% | 6.42 | 87.3 | 72 |
| Jun. | 27.5 | 26.9 | 27.6% | 7.64 | 86.8 | 67 |
| Jul. | 30.4 | 29.1 | 29.8% | 7.50 | 86.5 | 55 |
| Aug. | 29.2 | 28.1 | 29.0% | 6.92 | 86.8 | 49 |
| Sept. | 25.3 | 23.1 | 31.6% | 5.75 | 87.3 | 47 |
| Oct. | 18.5 | 16.0 | 39.2% | 4.25 | 87.9 | 47 |
| Nov. | 11.6 | 8.7 | 49.8% | 2.92 | 88.3 | 39 |
| Dec. | 5.6 | 2.9 | 61.2% | 2.25 | 88.5 | 35 |
| Annual | 17.2 | 15.3 | 41.8% | 4.92 | 87.6 | 53 |