Evapotranspiration Calculations
Pyrenees (Ben Nevis) - September 2025 daily calculations
| Date | Evapotrans- piration (mm) 0000- 2400 | Rain (mm) 0900- 0900 | Pan Evaporation (mm) 0900- 0900 | Max Temp | Min Temp | Max Rel Hum (%) | Min Rel Hum (%) | Average 10m Wind Speed (m/sec) | Solar Radiation (MJ/sq m) |
|---|---|---|---|---|---|---|---|---|---|
| 01/09/2025 | 1.4 | 0.6 | 9.6 | 3.4 | 99 | 72 | 2.96 | 12.60 | |
| 02/09/2025 | 1.4 | 0.0 | 10.5 | 4.4 | 99 | 71 | 3.70 | 9.96 | |
| 03/09/2025 | 1.8 | 0.2 | 12.5 | 4.7 | 99 | 57 | 3.57 | 12.36 | |
| 04/09/2025 | 1.3 | 0.4 | 8.4 | 3.5 | 100 | 72 | 5.36 | 10.18 | |
| 05/09/2025 | 1.9 | 2.6 | 9.1 | 0.8 | 95 | 58 | 4.78 | 16.94 | |
| 06/09/2025 | 3.5 | 0.0 | 16.2 | 2.9 | 83 | 43 | 9.19 | 14.04 | |
| 07/09/2025 | 2.4 | 0.2 | 14.3 | 7.4 | 98 | 52 | 10.66 | 4.20 | |
| 08/09/2025 | 1.8 | 5.0 | 13.2 | 5.7 | 99 | 66 | 3.90 | 12.85 | |
| 09/09/2025 | 1.9 | 0.0 | 12.1 | 4.9 | 99 | 65 | 4.91 | 14.06 | |
| 10/09/2025 | 1.3 | 0.2 | 7.9 | 2.9 | 99 | 77 | 5.63 | 11.50 | |
| 11/09/2025 | 0.9 | 1.0 | 7.9 | 2.5 | 100 | 91 | 7.46 | 10.84 | |
| 12/09/2025 | 1.6 | 1.0 | 11.8 | 2.7 | 100 | 71 | 6.05 | 12.16 | |
| 13/09/2025 | 1.9 | 0.4 | 13.7 | 5.0 | 99 | 71 | 3.27 | 15.07 | |
| 14/09/2025 | 3.1 | 0.0 | 15.6 | 6.7 | 85 | 51 | 6.06 | 18.38 | |
| 15/09/2025 | 4.8 | 0.0 | 19.7 | 9.6 | 73 | 32 | 7.32 | 18.75 | |
| 16/09/2025 | 1.6 | 1.2 | 12.0 | 6.5 | 100 | 66 | 3.74 | 10.26 | |
| 17/09/2025 | 1.7 | 2.4 | 9.6 | 2.0 | 99 | 67 | 4.37 | 14.33 | |
| 18/09/2025 | 2.9 | 0.2 | 15.0 | 3.8 | 91 | 46 | 4.72 | 17.94 | |
| 19/09/2025 | 3.2 | 0.4 | 15.9 | 8.2 | 98 | 42 | 6.01 | 16.25 | |
| 20/09/2025 | 1.9 | 1.2 | 10.2 | 1.3 | 99 | 62 | 7.09 | 14.31 | |
| Totals: | 42.3 | 17.0 |
