| Location | Angstrom Constants | Correlation Coefficients | Source | ||
| a | b | r | |||
| World | 0.23 | 0.48 |
| Black, et al. (1954) | |
|
| 0.25 | 0.5 |
| Glover, et al. (1958) | |
| Virginie (USA) | 0.22 | 0.54 |
| Penman (1948) | |
| South East England (Europe) | 0.18 | 0.55 |
| Penman (1948) | |
| Brisbane (Australia) | 0.23 - 0.35 | 0.38 - 0.54 |
| Cartledge (1973) | |
| Wagneningen (Netherlands) | 0.20 | 0.56 |
| Spitters (198) | |
| West-Africa | −0.12 - 0.26 | 0.99 - 9.50 |
| Davies (1966) | |
| Calabar (Nigeria) | 0.018 | 1.139 |
| Augustine C. (2009) | |
| Iseyia (Nigeria) | 0.20 | 0.75 |
| Falayi, et al. (2008) | |
| Cameroon | −0.04 - −0.14 | 0.74 - 1.13 |
| Mbiaké, et al. (2017) | |
| Douala (Cameroon) | −0.04 | 0.98 |
| Mbiaké, et al. (2017) | |
| Ngaoundéré (Cameroon) | −0.02 | 0.74 |
| Mbiaké, et al. (2017) | |
| Maroua (Cameroon) | −0.15 | 1.13² |
| Mbiaké, et al. (2017) | |