Purnia — AQI Trends
Year-over-year AQI trajectory for Purnia (2021–2024). Based on CPCB station data, 2016–present.
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Purnia — annual AQI 2021–2024
Year × month heatmap
Worst single days on record
- 2022-12-15Mariam Nagar (BSPCB)460
- 2022-12-14Mariam Nagar (BSPCB)450
- 2023-01-01Mariam Nagar (BSPCB)445
- 2023-01-23Mariam Nagar (BSPCB)435
- 2022-12-30Mariam Nagar (BSPCB)432
- 2022-12-13Mariam Nagar (BSPCB)431
- 2022-12-17Mariam Nagar (BSPCB)427
- 2023-01-21Mariam Nagar (BSPCB)423
- 2022-12-04Mariam Nagar (BSPCB)423
- 2023-01-14Mariam Nagar (BSPCB)422
What the numbers say
Overview
Purnia's AQI moved from 296 in 2021 to 133 in 2024 — a fall of 55.1% over 3 years. The long-run trend is improving, with a regression slope of -49.9 AQI points per year.
The data story
The worst recorded year in Purnia was 2021 at AQI 296, while the best was 2024 at AQI 133. The city has posted 35% of all measured days above AQI 200 (the Poor threshold), and its worst recorded single day hit 460 on 15 Dec 2022.
Why this pattern
The improving direction mirrors national NCAP (National Clean Air Programme) targets introduced in 2019, which aimed for a 20–30% PM reduction by 2024. Cleaner fuels, tighter vehicle standards, and the 2020 COVID lockdown year all show up in the yearly series. Sustained reduction past 2024 will depend on continued enforcement, industrial fuel switching, and controlling seasonal spikes from biomass burning and festivals.
What to do with this
For planners and residents, the trend matters as much as today's number. A worsening city needs aggressive source control and personal protection investments like indoor purifiers. An improving city rewards continued policy pressure but still requires caution during peak months. Use the live AQI page for day-to-day decisions and this chart for multi-year context. Year-over-year change of more than 10% in either direction is typically real signal, not noise.