The city’s maximum temperature dropped to 18.4°C, marking a sharp fall from Sunday’s 24.1°C and registering 2.3°C below normal.
While the past week’s nights have already been cold, daytime temperature drops are often felt more intensely by people due as its impact is usually felt when people are outdoors and active.
Weather scientists have forecast even more rain towards the weekend, which is expected to keep the day-time temperature considerably below what is considered normal this time of the year.
This is the first time since 2021, that the maximum has dropped below 20°C so early in winters, according to India Meteorological department (IMD) data. Last year, the maximum went below 20°C for the first time on December 29 with a reading of 19.8°C, and in 2022 on December 25, when the maximum fell to 16.2°C. In 2021, the temperature briefly fell below 20°C temperature on December 2.
An IMD official explained that persistent cloud cover reduced solar heating, causing Monday’s significant drop. “Generally cloudy skies persisted throughout the day. As a result, the heat penetration to the earth’s surface went down, leading to a dip in the maximum,” the officials said.
Conversely, the minimum temperature rose slightly to 8.6°C, one degree above normal, due to nighttime cloud insulation trapping heat near the earth’s surface.
Other areas in Delhi, such as Palam and Ridge, recorded higher minimums of 11.6°C and 10°C, respectively.
The drizzle, caused by a western disturbance, brought trace amounts of rain to Safdarjung, which is representative of Delhi’s weather. Other stations like Palam recorded 0.4mm of rain in the early hours and the trace amount of rain; Lodhi Road recorded trace amount of rain in the early hours followed by 0.3mm in the later part of the day; and Ayanagar recorded 0.4mm of rain till 5.30pm.
“The drizzle was due to the impact of the western disturbance. We might see some drizzle tomorrow. The second WD that will start affecting the region from December 26 is likely to cause widespread light to moderate rain along with thundershowers. The temperature might dip after that. The pollution level might go down as well, but it is also subject to the wind speed,” said Mahesh Palawat, vice president at Skymet.
IMD has issued a yellow alert for Tuesday and Wednesday, forecasting moderate fog across the city and dense fog in isolated areas. Drizzle is expected to continue, potentially contributing to evening smog. A following western disturbance, set to affect Delhi from Thursday, could bring more rain through Friday and Saturday, with IMD predicting widespread light to moderate showers.
The maximum temperature is likely to rise slightly, reaching around 20°C on Tuesday before dipping again after the rain. Minimum temperatures are expected to hover near 7°C for the next two days.
Despite the drizzle, Delhi’s air quality remained severe for the second consecutive day, with the Air Quality Index (AQI) at 406 on Monday, slightly better than Sunday’s 409 but still worse than Saturday’s “very poor” reading of 370. The Air Quality Early Warning System predicts gradual improvement, with the AQI expected to fall back into the “very poor” category by Tuesday and possibly moderate in the following days.
The Air Quality Early Warning System (AQEWS) for Delhi has forecast the air quality to improve to “very poor” by Tuesday again.
“The air quality is likely to be in very poor category from Tuesday to Thursday. The outlook for subsequent six days is that the air quality is likely to be in very poor to moderate category,” the AQEWS bulletin said on Monday evening.
