NOAA Climate.gov confirms La Niña has officially arrived, since the Niño3.4 index was about -0.7°C in October and atmospheric circulation is stronger than average. The sea-surface temperature signal is expected to persist for several overlapping three-month periods, though only just.
Official La Niña status signals a higher risk of drought for South America and the US southern Plains, which can support grain and oilseed prices.
After 1,079 past bullish weather events, Soybeans moved a median +0.3% over 5 sessions (54% higher; middle half -1.4% to +2.0%), and +0.9% over 20.
After 1,072 past bullish weather events, Wheat (SRW) moved a median +0.2% over 5 sessions (55% higher; middle half -1.4% to +2.3%), and +0.3% over 20.
Moves of each commodity's benchmark from the last close before the event. Historical reads pool past events of the same kind; they describe what happened, not what will. Not investment advice.