For Delhi residents, the rain over the last several days has provided relieve not just from the searing heat, but also from the city’s constant air pollution. On Thursday, Delhi achieved the cleanest air in over 300 days, with the 24-hour average air quality index (AQI) falling to 61 in the acceptable category. According to Central Pollution Control Board (CPCB) statistics, this is Delhi’s best air quality since September 11, 2023, when it was 53.
Weather experts attributed the improvement in air quality to on-and-off rain in the city during the last 24 hours, along with high winds. The rain continued to provide relieve from the heat. Because to the overcast sky throughout the day, the highest temperature in the city was 31.7 degrees Celsius (°C), which is six degrees lower than average for this time of year. The temperature was 34.1°C the day before, on Wednesday. On Thursday, Delhi’s lowest temperature plummeted to 24.8°C, three notches below usual. It was 29 degrees Celsius on Wednesday.

A day’s AQI value is obtained at 4 p.m., which is the average AQI for the previous 24 hours. On Wednesday, the 4 p.m. reading was 108 (moderate). Prior to Thursday, the lowest AQI of the year was 64 (acceptable) on June 28, after a record-breaking rainfall of 228.1mm in Delhi.
The CPCB classifies an AQI result between 51 and 100 as “satisfactory”, between 101 and 200 as “moderate”, between 201 and 300 as “poor”, between 301 and 400 as “very poor”, and above 400 as “severe”. The India Meteorological Department (IMD) predicts mild to moderate rains in the capital on Friday, with a yellow signal in effect. According to the IMD prediction, only isolated light rain is likely this weekend.

Weather updates: Wet period in Delhi creates traffic congestion; IMD anticipates heavy rain in these states.

“We saw spotty light rain in areas of Delhi in the early hours of Thursday. “A spell was also seen after noon on Wednesday, with wind speeds ranging from 10 to 25 kilometers per hour,” stated an IMD official.

According to Mahesh Palawat, vice president of private weather forecasting business Skymet meteorology, the monsoon trough is now north of Delhi and is expected to move away from the city on Saturday.
“On Friday, we may anticipate mild to moderate rains. Isolated areas of Punjab, Haryana, and Uttar Pradesh may even get significant rainfall. “The trough will move further north, closer to the foothills, and away from Delhi beginning Saturday,” he said.
During the monsoon season, Delhi has its finest weather of the year, when a mix of rain and strong winds helps settle and disperse pollutants. The period between July and September is also when Delhi has the best probability of having a “good” air day, with the AQI falling below 50. The last decent air day was on September 10, when the AQI was 45.

On Thursday, Delhi had moderate to light rains, with total rainfall in the 24 hours before 8.30am amounting to 9.2mm at Safdarjung, 17.4mm at Palam, and 40.8mm at Ayanagar. On Thursday, between 8.30 a.m. and 5.30 p.m., Safdarjung recorded 0.6mm, Palam 0.2mm, and Ayanagar 2.1mm.

Safdarjung has not seen any rain in the first three days of the month. Since the monsoon arrived in Delhi on June 28, with 228.1mm recorded, ‘trace’ rainfall has been reported on June 29 and 8.9mm on June 30.
The forecast for Friday suggests that Delhi will have mild to moderate rain throughout the day, with a maximum and lowest temperature of 33 and 26°C, respectively.