Scorching Nights: Why Minimum Temperatures Stay Above 30 °C Across Delhi, Jaipur, and Ahmedabad

It feels like the day never really ends. While the sun sets, the mercury refuses to dip –‑ night‑time lows in parts of North‑West India are lingering at or above 30 °C, a figure that used to belong only to the hottest afternoons.

Meteorologists at the India Meteorological Department (IMD) say a “blocking high” over the northern plains is the primary driver. Think of it as a giant lid that traps warm air, preventing cooler breezes from moving in. This high‑pressure system has been hanging around for more than a week, nudging the whole region into a prolonged spell of heat.

But it’s not just the weather aloft that’s at fault. Cities like Delhi and Ahmedabad are built on concrete, asphalt and glass – materials that store heat during the day and release it slowly after dark. The so‑called urban heat island effect adds another 2‑3 °C to the night‑time temperature, turning a warm evening into a sweltering one.

Adding a dash of humidity doesn’t help either. Moist air acts like a blanket, holding onto the heat. Recent satellite data shows relative humidity hovering around 70 % in the early evening, especially over the Gujarat coast, which keeps the night air from cooling off as it normally would.

Some scientists point to a longer trend: climate change is nudging the baseline temperature higher. Over the past 30 years, the average minimum temperature during May has crept up by about 0.9 °C in Delhi. While a fraction of the current night‑time heat can be blamed on natural variability, the background warming makes extreme events more likely.

What does this mean for residents? Comfort levels drop dramatically when night‑time heat stays high –‑ sleep becomes restless, and the body struggles to recover from daytime exertion. Hospitals are already reporting a spike in heat‑related ailments, from dehydration to heat‑stroke, especially among the elderly.

Authorities are urging people to stay hydrated, use fans or coolers, and avoid outdoor activities after sunset. Some cities have opened cooling centres, while others are experimenting with mist‑spray installations along busy streets.

Looking ahead, the IMD predicts the blocking high may linger into early June, keeping min‑temps stubbornly high. However, a gradual shift in wind patterns could finally bring a sigh of relief, ushering cooler breezes from the northwest.

In the meantime, the heatwave serves as a stark reminder that our cities are not just dealing with hot days but also uncomfortably hot nights. Adaptation measures, from greener rooftops to better urban planning, might be the only way to reclaim a cooler night‑time for the millions who call this region home.