Table 1.
Monthly averages of daily ambient ultraviolet radiation in minimum erythemal dose units*, 1996-2000, for capital cities of Australian states included in 1981 multiple sclerosis survey (data provided by H P Gies, personal communication) (capital city latitudes shown in decimal degrees in parentheses)
| Brisbane (Qld) (27.5º S) | Perth (WA) (31.9º S) | Sydney (NSW) (33.9º S) | Adelaide (SA) (34.9º S) | Hobart† (Tas) (42.9º S) | |
|---|---|---|---|---|---|
| January | 24.7 | 30.4 | 22.2 | 28.1 | 20.4 |
| February | 22.3 | 27.9 | 21.7 | 24.5 | 18.6 |
| March | 19.0 | 18.9 | 16.2 | 13.7 | 12.4 |
| April | 12.5 | 11.8 | 9.8 | 9.4 | 6.5 |
| May | 8.6 | 7.1 | 5.6 | 5.2 | 3.7 |
| June | 6.6 | 4.9 | 3.9 | 3.6 | 1.7 |
| July | 7.5 | 5.4 | 4.1 | 3.7 | 1.6 |
| August | 10.4 | 7.9 | 6.9 | 6.3 | 3.9 |
| September | 14.6 | 12.1 | 10.4 | 10.0 | 7.0 |
| October | 18.9 | 18.8 | 15.3 | 15.5 | 12.0 |
| November | 22.7 | 23.8 | 19.1 | 21.5 | 15.7 |
| December | 24.4 | 29.2 | 21.9 | 26.1 | 18.1 |
| Seasonal variation‡ | |||||
| Max:min | 3.7 | 6.2 | 5.7 | 7.8 | 12.8 |
*Minimum erythemal dose is measure of ultraviolet radiation exposure required to induce erythema or sunburn.28
†1991 data.28
‡Seasonal variation as given by ratio of summer maximum to winter minimum ultraviolet radiation.