New Delhi, Oct 6 (PTI) Delhiites woke up to a pleasant windy and cloudy morning on Thursday as the weather office predicted light rain and thundershowers during the day. Rains are likely to further improve the air quality index (AQI) which according to the Central Pollution Control Board (CPCB) data was in the moderate category with index value measured at 134 at 8 am on Thursday. According to CPCB"s 24 hour AQI bulletin at 4 pm on Wednesday, the air quality was in the poor category with index value at 211. An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe. With the air quality in Delhi dropping to the "poor" level on Wednesday, authorities in the National Capital Region have been asked to strictly implement measures under the first stage of the Graded Response Action Plan (GRAP). The action plan includes penal and legal action against polluting industrial units. According to the India Meteorological Department (IMD), the minimum temperature of Thursday was recorded at 22.4 degrees Celsius, one notch above the season"s average. "There will be generally cloudy sky with light rain and thundershowers. The maximum temperature of the day is likely to hover around 33 degrees Celsius," an IMD official said. The relative humidity at 8.30 am was 83 per cent, the weather office said. Under Stage-I, the Centre"s Commission for Air Quality Management (CAQM) recommends stopping construction and demolition (C&D) activities at sites having plot size equal to or more than 500 square metres that are not registered on the "web portal" of the respective states for remote monitoring of air pollution levels.        Project proponents are required to ensure proper implementation of guidelines for dust mitigation, management of C&D waste and use of anti-smog guns at construction sites. PTI AKM CK