Article3: Early Summer & Climate Variability
Why in News: Several regions of India witnessed unusually early heatwave-like conditions in March 2026 due to deficient winter rainfall and reduced Western Disturbances.
Key Details
- Temperatures in parts of North and West India rose 8–13°C above normal, indicating early heatwave conditions.
- January–February 2026 rainfall was about 60% below normal, making February the third driest since 1901.
- Reduced Western Disturbances led to weak snowfall and rainfall in the Himalayan region.
- Early heat is expected to affect rabi crops such as wheat, mustard, gram, and horticultural produce.
Early Summer and Rising Temperature Trends
- Unusual temperature rise in March: Several regions recorded temperatures 8–13°C above normal, which is unusual for early March. Cities in Himalayan regions like Shimla experienced temperatures above 25°C, normally seen only in May or June.
- Heatwave-like conditions: According to the India Meteorological Department (IMD), heatwave conditions occur when temperatures exceed normal by 4–6°C or more. Early March temperatures already approached these thresholds in parts of north and west India.
- Changing seasonal patterns: Traditionally, the winter-to-summer transition occurs gradually between March and April. However, early temperature spikes indicate changing climate variability and seasonal shifts.
- Regional variation: States such as Gujarat, Himachal Pradesh, Jammu and Kashmir, and Andhra Pradesh experienced higher-than-normal temperatures, reflecting the uneven distribution of climatic impacts across India.
Role of Western Disturbances in India’s Winter Climate
- Nature of Western Disturbances: Western Disturbances are eastward-moving extra-tropical cyclones originating near the Mediterranean region, carrying moisture towards India during winter.
- Source of winter rainfall: These systems are responsible for 70–80% of winter rainfall in northwestern India, including states such as Punjab, Haryana, Himachal Pradesh, and Jammu & Kashmir.
- Impact on Himalayan snowfall: Snowfall in the western Himalayan region largely depends on these disturbances. Reduced disturbances in winter 2025–26 led to low snowfall and rainfall.
- Agricultural importance: Winter rainfall from Western Disturbances provides critical moisture for rabi crops, especially wheat and mustard in north India.
Dry Winter and Declining Rainfall Trends
- Rainfall deficit in 2026: India received only 16 mm rainfall in January–February 2026, about 60% below the long-term average, making it one of the driest winters in more than a century.
- Weak weather systems: Meteorologists observed fewer Western Disturbances and weak wind convergence, reducing moisture inflow from seas to the Indian landmass.
- Impact on soil moisture: Lack of rainfall reduces soil moisture content, causing land surfaces to heat faster when summer approaches.
- Climate variability: Increasing climate variability and warming trends may influence the frequency and intensity of winter weather systems.
Link Between Soil Moisture and Temperature Rise
- Evaporation cooling effect: Normally, when soil contains moisture, the initial heat energy is used for evaporation, delaying the rise in temperature.
- Dry soil heats faster: In the absence of rainfall, dry land absorbs and retains heat quickly, causing rapid temperature rise and early summer conditions.
- Amplified heatwave risk: Reduced soil moisture increases the likelihood of prolonged heatwaves and higher daytime temperatures.
- Urban heat island effect: In cities, concrete infrastructure further traps heat, intensifying the effects of early summer and rising temperatures.
Impact on Agriculture and Water Resources
- Threat to rabi crops: Crops such as wheat, mustard, gram, sorghum, sesame, and groundnut are highly sensitive to temperature spikes during their growth stages.
- Reduced crop productivity: High temperatures during the grain-filling stage of wheat can reduce yields significantly by shortening crop maturity periods.
- Increased irrigation demand: Farmers are advised to increase irrigation to maintain soil moisture levels, which may increase pressure on groundwater resources.
- Impact on horticulture: Fruits such as apples and vegetables like potatoes are vulnerable to temperature stress, affecting both productivity and quality.
Conclusion
India must strengthen climate-resilient agriculture and weather forecasting systems to cope with increasing climatic variability. Improving irrigation efficiency, adopting heat-resistant crop varieties, and enhancing monitoring of Western Disturbances are crucial steps. Long-term strategies focusing on climate adaptation, sustainable water management, and early warning systems will help mitigate the impacts of early summer and extreme temperature events.
EXPECTED QUESTIONS FOR UPSC CSE
Prelims MCQ
Q. Western Disturbances are important for which of the following in India?
- Winter rainfall in northwestern India
- Snowfall in the Himalayan region
- Moisture supply for rabi crops
Select the correct answer:
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1, 2 and 3
(d) 1 only
Answer: (c)