Southwest Monsoon has withdrawn from most parts of Northwest and Central India leading to clear sky conditions. We are currently in the transition phase, moving from Monsoon to post-Monsoon period. Post-Monsoon period basically refers to the months of October and November.
Diurnal temperature variation is on the higher side over parts of West Uttar Pradesh, Madhya Pradesh, and Vidarbha region. The difference between maximum and minimum temperature is settling around 16 to 17°C these days.
The wide gap between maximum and minimums is also responsible for triggering various medical problems like cold, flu, allergies, etc. Thus, care and caution must be maintained at morning and night.
The day temperature is settling in the 30s due to a prolonged dry spell and clear sky conditions. The incoming solar radiation exceeds the outgoing long wave radiation from the Earth’s surface. As the sky is clear, the outgoing long wave radiation is also high.
On a cloudy night, the outgoing long wave radiation gets trapped between Earth’s surface and clouds resulting in less cooling at night. This effect is called the greenhouse effect. But as the sky over most parts of Northwest and Central India is clear, the minimums in these parts keep decreasing as the long wave radiation escapes at night.
Currently, many places in the country are observing high diurnal variation. Agra (Maximum 39°C, Minimum 19°C), Lucknow (Maximum 38°C, Minimum 20°C), Gwalior (Maximum 38°C, Minimum 23°C), and Nagpur (Maximum 37°C, Minimum 20°C) are examples of places experiencing high diurnal variation.
