Statistics Indonesia (BPS) reported annual inflation of 3.28% for September 2026 and a Consumer Price Index (CPI) of 112.31. The year-on-year rate in the release published on 1 October measures the price-level change against September 2025. It is distinct from the change within September: month-on-month inflation was 0.30%. The increase from the end of 2025 through September, described as year to date, was 2.17%. These three rates refer to different comparison periods and should not be used interchangeably.

BPS also reported core inflation of 2.84% year on year, 0.10% month on month and 2.07% year to date. The core series is not the same measure as the headline CPI; the agency presents it as a separate component alongside the broader consumer basket. Nor does an index level of 112.31 mean inflation was 112.31%. The index level describes the price level relative to its defined base, while inflation rates express percentage changes between two periods.

At provincial level, North Sulawesi recorded the highest annual rate, 7.59%, and a CPI of 116.58. South Sumatra had the lowest provincial rate, 2.55%, with a CPI of 112.21. The extremes at regency or city level were different: North Minahasa had annual inflation of 9.05% and an index of 121.70; South Central Timor recorded 1.04% and an index of 108.48. The national rate of 3.28% therefore does not mean that every region experienced the same price change. The release highlights these highest and lowest observations rather than describing every local result in its short abstract.

The CPI measures changes in a consumer-level basket of goods and services. BPS’s methodological framework uses 2022=100 beginning in January 2024, following updates connected to consumption patterns and coverage. The published index covers Indonesia nationally and is also reported for geographic subdivisions. Its rates should not be confused with individual product prices, producer prices or wholesale prices. Inflation is a statistical summary of consumer-level price movements; it does not represent an identical spending basket or budget impact for every household.

The annual rate describes the change over the preceding twelve months, the monthly rate compares August with September, and year-to-date inflation captures the cumulative movement from the end of 2025 through September 2026. BPS presents these measures in the same release while keeping their reference periods distinct. Core rates are reported over the same types of periods but refer to a separate component. These are official price statistics for September, not a forecast of future inflation. The highest and lowest regional observations also do not describe the full distribution across all regions. A comparison should keep the index level, time basis and geographic scope in view.