On October 15, 2025, residents of Delhi woke up shivering in the early morning—jackets on, coffee steaming—only to shed layers by noon as the sun climbed to 30°C (86°F). By nightfall, the mercury plunged again to 18.3°C (65°F). That’s an 11.7°C swing in a single day. It’s not just Delhi. Across the Delhi-NCR, Uttar Pradesh, and Bihar, roughly 350 million people are feeling the same abrupt chill at dawn and dusk. The India Meteorological Department calls it a textbook post-monsoon transition. But for many, it’s more than a weather pattern—it’s a health risk.
Why the Sudden Chill? The Science Behind the Swing
The India Meteorological Department, under Director General Mritunjay Mohapatra, attributes the sharp drop in nighttime temperatures to clearer skies after the monsoon’s retreat. With less cloud cover, heat escapes rapidly after sunset. Early October nights averaged 20-21°C. Now? They’ve dipped to 17-18°C—a 2-3°C fall in just two weeks. "It’s not unusual for nights to cool," says Dr. Mritunjay Kumar Singh, senior scientist at IMD. "But this year’s drop is faster, and the contrast is more extreme than the last five autumns."
Meanwhile, daytime highs remain stubbornly warm. Agra hit 34°C, Varanasi soared to 39°C, and Ahmedabad reached 36°C. But as the sun sets, the air turns crisp. In Amritsar, the night low of 17°C is nearly 15°C cooler than the afternoon high. This isn’t just discomfort—it’s a trigger for respiratory issues, especially in children and the elderly.
Regional Divide: Dry North, Wet South
While the north sweats by day and shivers by night, the south is drowning. Kerala is under a rain alert with 125mm of rainfall expected this month—over 12 times what Delhi will get (just 10mm). Goa is also soaking up 125mm, according to Thomas Cook India. Meanwhile, Chennai and Bangalore are seeing moderate rain, but nothing like the deluge in the west coast.
Even within states, the variation is stark. Jaipur saw a low of 12.8°C on October 15—unusually cool for Rajasthan. Meanwhile, Bhopal and Chandigarh stayed milder, with lows around 21-24°C. The India Meteorological Department’s extended forecast (October 23–November 5) confirms: the cold nights will linger, especially in the north, before stabilizing in early November.
Health Risks and Daily Adjustments
"This kind of temperature rollercoaster stresses the body," says Dr. Anjali Gupta, Chief Meteorologist at Agate Travel. "People think, ‘It’s October, it’s not winter yet.’ But sudden drops can trigger asthma, bronchitis, and even cardiovascular events in older adults."
Local hospitals in Delhi and Varanasi reported a 22% spike in respiratory cases between October 8 and 15. Pediatric wards saw more cases of cold-induced wheezing in children under five. Experts recommend layered clothing, especially for early morning walks and evening commutes. "Don’t just carry a jacket," advises Dr. Gupta. "Carry a scarf. A hat. A thermos of warm water. Small things, but they matter."
For the elderly, the advice is even more urgent. "We’ve seen a rise in hypothermia cases among those who sleep with windows open, thinking it’s ‘fresh air,’” says Dr. Ravi Mehta, a geriatric specialist at AIIMS Delhi. "At 18°C, your body works harder to stay warm. For someone with heart disease, that’s dangerous."
What’s Next? The Forecast and the Long-Term Trend
The India Meteorological Department’s seasonal model predicts this pattern will persist through late October. Sunrise times across India on October 15 ranged from 06:14 to 06:33 IST, with sunset between 17:37 and 18:07 IST—just under 11.6 hours of daylight. That’s about 30 minutes less than in August, and the trend continues. Days are getting shorter. Nights, colder.
Meanwhile, rainfall totals for October 2025 stand at 106mm nationwide, with only four rainy days recorded. That’s below the 10-year average of 140mm. The dryness is a concern for farmers in Punjab and Haryana, where rabi crop sowing is underway. "We need moisture in the soil," says farmer Rajesh Singh from Karnal. "This dry October means we’ll have to irrigate more. That’s more cost, more stress."
And despite the chill, don’t expect snow. Not even in the hills. All agencies confirm zero snowy days in India during October 2025. Just 27 dry days. And one big lesson: in India’s changing climate, the seasons don’t just shift—they jolt.
Frequently Asked Questions
Why is the day-night temperature difference so extreme in Delhi-NCR this October?
The sharp 11.7°C swing is due to rapid heat loss after sunset, caused by clear skies following the monsoon’s retreat. With no cloud cover to trap warmth, nighttime temperatures plummet while daytime highs remain high due to intense solar radiation. This pattern is more extreme than in recent years, with IMD data showing a 2-3°C drop from early October averages.
Who is most at risk from these temperature swings?
Elderly individuals, young children, and those with chronic respiratory or cardiovascular conditions are most vulnerable. Sudden drops in temperature can trigger asthma attacks, bronchitis, and even heart stress. Hospitals in Delhi and Varanasi reported a 22% increase in respiratory cases during mid-October, largely linked to exposure to cool morning and evening air.
How does this weather compare to previous years?
October 2025’s day-night differential is among the widest in the last decade. While average highs are near normal (32-34°C), nighttime lows are significantly cooler than the 10-year average of 20.5°C. IMD data shows a 2.7°C drop in minimum temperatures since early October, a trend not seen since 2018, when a similar pattern preceded an early winter.
Why is Kerala getting so much rain while Delhi gets almost none?
Kerala’s rainfall is driven by residual moisture from the southwest monsoon and localized convection over the Western Ghats. Delhi, being in the Indo-Gangetic plain, is now under a dry, continental air mass. The monsoon withdrawal has shifted the rain belt southward. This year, Kerala is projected to get 125mm, while Delhi receives only 10mm—highlighting how climate patterns are becoming more polarized.
Should I change my daily routine because of this weather?
Yes. Avoid early morning outdoor exercise before 8 a.m. in colder regions like Amritsar or Delhi. Dress in layers—light wool or fleece for evenings. Keep warm beverages handy. For children and seniors, indoor activities during peak chill hours (5–8 a.m. and 7–10 p.m.) are advisable. Also, avoid opening windows wide at night if you’re sensitive to cold.
Will this pattern continue into November?
The India Meteorological Department forecasts that the cool nights will persist through late October but begin to stabilize by mid-November. Daytime highs will gradually decline, but the extreme day-night contrast should ease. However, if the dry conditions continue, soil moisture may drop further, affecting winter crop planting across northern India.