That was faster than the 78.2% median estimate from analysts, and marks a new three-decade high, according to government data published Wednesday. Consumer prices rose 7% from a month earlier.

Clothing prices rose 109% from a year earlier, while food costs increased by 80%. Worse may be to come, since the government raised regulated utility prices in September, which will have a knock on effect in several sectors.

What Bloomberg Economics Says

"Monetary tightening won't suffice to cool price gains in the near term. Energy subsidy cuts and pass-through from faster peso depreciation will push inflation near 90% by year-end."

--Adriana Dupita, Latin America economist

Central bank officials are widely expected to raise borrowing costs this week. The monetary authority has started hiking more aggressively since Economy Minister Sergio Massa took over in early August. Keeping rates above inflation is also a key pillar of Argentina's $44 billion program with the International Monetary Fund. The benchmark rate currently stands at 69.5%.

Massa met Monday with IMF Chief Kristalina Georgieva in Washington, committing to implement the program. Massa also told reporters afterward that bringing inflation down is one of the government's top priorities.