In December 2020, Egypt, Australia, and Argentina are currently in season.
The North of Vietnam, on the other hand, has a monsoonal climate with a cold winter from November to February. Therefore, typically there are three main production seasons for sweet potato in this season: 1) Winter-Spring season with plantation time from November - December and harvesting time from April - May next year; 2) Winter season with plantation time from September - October and harvesting time from January - February next year and 3) Spring season with plantation time from February - March and harvesting time from June - July.
Sweet potatoes can be grown throughout the year, but drought can be avoided if farmers want to reduce their losses because every time, drought is reduced by 30% if not supplied enough water.
Sweet potato is usually planted at the beginning of the rainy season (June - November). But for areas with no distinct wet and dry season and having evenly distributed rainfall, the sweet potato could be planted any time of the year.
The production of sweet potatoes in the US also occurs during the dormant season in Louisiana from July to October (Stark, 2019).