The 39th parallel south is a circle of latitude that is 39 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America.
Daylight along the 39th parallel south falls under 10 hours a day starting on 17 May and returns to over ten hours a day beginning 29 July. Crops and other plant growth is considerably slowed during this period of reduced sunlight.
Starting at the Prime Meridian and heading eastwards, the parallel 39° south passes through:
| Co-ordinates | Country, territory or ocean | Notes | |
|---|---|---|---|
| Atlantic Ocean | |||
| Indian Ocean | Passing just south of Île Saint-Paul, | ||
| Indian Ocean | Bass Strait | ||
| Victoria - Wilsons Promontory | |||
| Pacific Ocean | Tasman Sea | ||
| Taranaki region – passing through Waitara Manawatū-Whanganui region Waikato region – passing just south of Tūrangi Bay of Plenty region – for about 2km (01miles) Hawke's Bay region | |||
| Pacific Ocean | |||
| Araucanía Region – passing through Teodoro Schmidt and Sollipulli Volcano | |||
| Neuquén Province Río Negro Province – passing through General Roca (at) La Pampa Province Buenos Aires Province – passing through Bahía Blanca (at) | |||
| Atlantic Ocean |