There isn't one, and any page that names a single best month is simplifying to sell you something. The season runs from early November to mid March, and the whole of it is good in different ways. What changes across those months is what you'll see: pristine snow and courtship early, fluffy chicks and whales in the middle, and active wildlife with the best pricing late.
The useful way to decide is to pick your one priority and let it choose the month.
| If you want | Go |
|---|---|
| Untouched snow, sea ice, courting penguins | Early to late November |
| Penguin chicks and 24 hour daylight | Mid December to January |
| Chicks on the move, whales, leopard seals | February |
| Whale encounters, photography light, best pricing | March |
Some operators start in October on South Georgia repositioning runs and a few push into April. Those edges shift depending on who's sailing, so check the specific season rather than treating the boundaries as fixed.
The seasons blend into each other. The one real break is around mid February, when the character of the trip shifts from penguin colonies to whales and predation.