Special report


January 25th, 2021
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La Niña 2020/2021 Impacts in Argentina & Brazil


  • La Niña conditions began in August-September 2020 and are currently forecast to continue from January to March (~95% chance) and then with a possible transition to neutral conditions from April to June (~55% chance).
  • Argentina and Brazil are key producers and exporters of maize and soybean, among other crops, and current conditions are affecting the production prospective.
  • Argentina’s early-planted maize has experienced dry conditions while late-planted maize is under generally favourable conditions. Spring and summer-planted soybeans have suffered a similar fate to maize; however, they have slightly better yield expectations than maize.
  • We are a few weeks away from the beginning of critical stages for late-planted maize and soybean in Argentina.
  • In Brazil, both spring-planted maize and soybeans started the season with a delay due to the early dry conditions. Currently, spring-planted maize is under mixed conditions while soybeans are under generally favourable conditions.
  • Summer-planted maize sowing in Brazil is on schedule and an average planted area total is expected.
  • The situation in both Argentina and Brazil is stable, but it remains fragile. If the soil moisture in the coming weeks does not match the growing needs of the crops, yields could be impacted.


Figure 1: Cumulative precipitation compared to the 5 year mean in select main producing provinces/states of Argentina and Brazil. Rainfall deficits can be seen since the start of the season for all regions. Source: NASA Harvest.

La Niña 2020/2021

Beginning in August-September 2020, the El Niño-Southern Oscillation (ENSO) La Niña phase developed and is currently ongoing. At this time, La Niña conditions are forecast to continue from January to March (~95% chance) and then with a possible transition to neutral conditions during April to June (~55% chance) . During the expected peak period of November-December-January, the current La Niña is forecast to be of moderate strength, based on a three-level system (weak, moderate, strong) using a 3-month running mean of sea surface temperature anomalies . The stronger the event, the larger the changes in weather patterns that typically occur.

In South America, La Niña events can typically bring above-average rainfall across the north of the continent, while below-average rainfall can typically occur further south along the eastern and western coasts. The current La Niña event is exhibiting a similar pattern, with rainfall since September showing areas of above-average rainfall across the northern regions of the continent while areas of below-average rainfall in the central and southern regions (Figure 2).

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Figure 2: Monthly rainfall anomalies over South America during the beginning of the 2020-2021 crop season. A: September anomaly showing early season deficits in parts of central and southern Brazil along with eastern Paraguay. B: October rainfall deficits primarily in central and eastern Argentina, southern Brazil, eastern Paraguay, and across Uruguay. Above-average rainfall occurred in parts of central and eastern Brazil. C: November rainfall deficits in central and eastern Argentina, central and southern Brazil, eastern Paraguay, and across Uruguay, D: December (Preliminary) rainfall deficits in eastern and northern Argentina, northeast and the very south of Brazil, and in southern Uruguay. Additionally, in December there were pockets of above-average rainfall across central Brazil. Anomaly data compares 2020 rainfall amounts to the 1981-2019 CHIRPS average. Data obtained from https://www.chc.ucsb.edu/data/chirps


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