Delhi's nights are not cooling the way they used to. Power demand shows it

As minimum temperatures stay higher later into the night, cooling demand also lasts longer.

As the national capital enters another peak summer, the heat lingers long past sunset. But while a few warmer nights may not seem unusual, the city’s electricity demand data indicates something more.

Minimum temperatures between March and May have been staying higher for longer in recent years, with several nights in 2025 and 2026 recording above 25 degrees Celsius well into late April and May. This shift is now evident in Delhi’s electricity demand patterns too.

For years, Delhi’s peak power demand usually arrived in the afternoon, when offices and commercial areas were running during the hottest part of the day. But analysing March-April-May data from the Delhi State Load Dispatch Centre between 2023 and 2026 shows the city’s peak demand is steadily shifting into the evening and night.

In 2023, most daily peaks occurred late morning and afternoon, with the average peak demand time around 10.30 am. By 2026, many were in the evening or close to midnight, and the average peak demand time had shifted to nearly 2.30 pm.

The shift becomes much sharper as Delhi moves deeper into summer. In April 2023, the average daily peak demand occurred around 3 pm. By 2025 and 2026, it had moved beyond 5.30 pm. In May 2024, the average peak demand time also moved past 8 pm.

The shift closely tracks Delhi’s rising nighttime or minimum temperatures. As minimum temperatures stay higher later into the night, cooling demand also lasts longer. Instead of easing after sunset, electricity consumption remains high well into the evening.

The trend becomes even clearer in the number of very late-night peaks. Between March and May 20, Delhi recorded only eight days in 2023 when peak electricity demand happened after 11 pm. The number jumped to 13 in both 2024 and 2025. In 2026, there have so far been 12 such days.

Electricity consumption itself has also risen sharply in just three years. A comparison of Delhi’s power demand on May 21 in 2023 and 2026 shows this. In 2023, demand during the early morning hours fell to nearly 3,700 MW before gradually rising through the afternoon. By contrast, in 2026, demand during the same pre-dawn hours remained above 5,000 MW and climbed beyond 8,000 MW during the day.

Delhi’s changing demand pattern may be part of a much larger shift underway across India. On May 21, the Ministry of Power announced that India had recorded its fourth consecutive day of all-time high “solar hour” peak demand. The country’s peak demand touched 270.82 GW. The ministry directly linked the surge to increased use of cooling appliances due to prevailing heat across the country.

The demand for cooling is expected to rise sharply in the coming decades. According to the International Energy Agency, the global stock of air-conditioners could rise from around 1.6 billion units in 2018 to 5.6 billion by 2050. India is expected to account for a major share of that growth as harsher summers push more households towards air-conditioning.

The IEA has also warned that cooling is now becoming the fastest-growing use of electricity in buildings worldwide. Without major efficiency improvements, electricity demand for cooling alone could more than triple by 2050.

Even today, only around 8–10 per cent of Indian households own air conditioners, according to estimates cited by the IEA and cooling policy groups. But ownership is on the rise.

What Delhi is witnessing may be an early sign of how rising temperatures are reshaping electricity use in Indian cities.

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