FX.co ★ French Inflation Turns Negative in September as CPI Falls 0.3% MoM

France’s consumer price dynamics shifted sharply in September, with the monthly Consumer Price Index (CPI) dropping by 0.3% compared with the previous month, according to data updated on 15 October 2026. The move marks a notable reversal from the prior month’s 0.7% month-on-month increase, highlighting a rapid cooling in short-term inflation momentum.

Both the current and previous readings relate to September 2026, but capture different month-over-month comparisons. The latest figure shows that, relative to August, prices declined on average in September, whereas the earlier 0.7% reading reflected a strong rise in prices in the preceding month-over-month period. This swing from robust monthly inflation to a mild contraction in prices suggests shifting price pressures within the French economy.

Investors and policymakers will be closely watching whether the negative monthly print signals a temporary correction after earlier price gains or the start of a more sustained disinflationary trend. The month-over-month basis used for this comparison underscores the short-term volatility in consumer prices, which can be particularly relevant for central bank rate expectations and near-term inflation outlooks.