New Delhi, Feb 8 (IANS): The overall air quality of Delhi improved to the 'moderate' category on Thursday after being in the 'poor' and 'very poor' category for days, due to rains and high wind.

According to the Central Pollution Control Board (CPCB) data, the air quality index (AQI) of the city was at 176, which falls in the 'moderate' category, a significant drop from the AQI of 349 recorded on Wednesday, which falls in the 'very poor' category.

An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and between 401 and 500 'severe'.

While according to the System of Air Quality and Weather Forecasting (SAFAR), the overall AQI was recorded at 166. None of the areas in the city recorded 'very poor' or 'severe' air quality.

The level of PM2.5 -- particles in the air with a diameter of less than 2.5 micrometres -- was recorded at 76 and the PM10 level was at 119, it said.

The authorities said southwesterly winds from the Arabian Sea will bring more moisture to the capital.

The AQI will remain moderate on Friday also, it added.