Raging fires have devoured some 6,000 hectares (14,800 acres) of forests in Corrientes Province in just days, officials reported Tuesday.
Three fires continued to threaten while two others were burning but under control, according to the emergency command centre of Corrientes.
No injuries have been reported and the fires have not spread to populated areas, with rains expected Tuesday.
Since the start of the year Argentina has faced heat wave after heat wave with a crushing drought destroying crops. Fires have destroyed more than 100,000 hectares in Corrientes, according to the INTA agricultural technology institute.
Last month, Argentina issued health warnings in several provinces under the worst heat wave in decades, with temperatures close to 40 degrees Celsius (104 Fahrenheit).
The three months from November to the end of January were the warmest such period since 1961, according to the weather service.
While occasional heat waves are normal, climate change has made them "more persistent and more intense," even in Argentina's mountainous Patagonia region, meteorologist Enzo Campetella told AFP last month.
In 2022, forest fires in Corrientes burnt more than a million hectares, according to official figures.
The La Nina cycle of the El Niño weather phenomenon brought historically high temperatures last year, leading to crop losses estimated in the billions of dollars.