According to an India Meteorological Department (IMD) forecast, due to the early arrival of monsoon in the national capital this week, Delhi is likely to see thunderstorms with rain on Monday, with maximum and minimum temperatures likely to be lower than normal.

On Monday, the minimum temperature is expected to be 25 degrees Celsius, with a maximum temperature of 34 degrees Celsius. On Sunday, the minimum temperature was 23.8°C, four degrees below normal, and the maximum temperature was 35.2°C, also four degrees below normal.

The monsoon is expected to cover most of northwest India by Tuesday, according to IMD officials. “Conditions are favourable for the southwest monsoon to advance further into most parts of Madhya Pradesh, remaining parts of east Uttar Pradesh, Delhi, more parts of west Uttar Pradesh, Haryana, and Punjab over the next 48 hours,” said Kuldeep Srivastava, the head of IMD’s regional weather forecasting centre.

The monsoon was two weeks ahead of schedule, due to a low-pressure system forming over the Bay of Bengal, and was expected to reach Delhi and most of northwest India by June 15. By June 27-28, the southwest monsoon has usually arrived in Delhi.

In the meantime, Delhi’s air quality was satisfactory on Monday morning. The hourly air quality index (AQI) at 7 a.m. was 100, according to data from the Central Pollution Control Board. The average 24-hour AQI on Sunday was 83, which is also in the satisfactory range.

An AQI of zero to fifty is considered “good,” 51 to one hundred “acceptable,” 101 to 200 “moderate,” 201 to 300 “poor,” 301 to 400 “very poor,” and 401 to 500 “severe.”

The air quality in the nation’s capital is expected to remain “satisfactory” this week due to the rain. “Rainfall observed yesterday [Saturday] has led to air quality improvement,” the Union ministry of earth science’s air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (Safar), said on Sunday. For the next three days, the wind speed is expected to remain high, and isolated rain is expected in Delhi. The AQI is expected to improve and remain in the satisfactory range for the foreseeable future.