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. The growth of crops and other plants is considerably slowed during this period of reduced sunlight.

Around the world

Starting at the Prime Meridian and heading eastwards, the parallel 39° south passes through: ! scope="col" width="125" | Coordinates ! scope="col" | Country, territory or ocean ! scope="col" | Notes ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean ! scope="row" style="background:#b0e0e6;" | Indian Ocean ! scope="row" style="background:#b0e0e6;" | Indian Ocean ! scope="row" | 🇦🇺 ! scope="row" style="background:#b0e0e6;" | Pacific Ocean ! scope="row" | 🇳🇿 ! scope="row" style="background:#b0e0e6;" | Pacific Ocean ! scope="row" | ! scope="row" | 🇦🇷 ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean