Seasons of India
India's four seasons: cold weather and western disturbances, hot weather and local storms (loo, mango showers, kalbaisakhi), the rainy season and the retreating monsoon.
Prerequisites
- Mechanism of the Indian Monsoon — the ITCZ, the jet streams and the onset and withdrawal dates that define the seasons.
- Physiography of India — relief explains why the same season feels different in Leh, Kolkata and Chennai.
The Hook: Hareli, Cherchera and the Weather Calendar
A Chhattisgarh farming family’s year runs on the weather. Hareli (हरेली) in Sawan celebrates the green fields after the rains begin. Cherchera (छेरछेरा) in Paush comes after the paddy harvest, in the cool dry season. In May the plains swelter, and in December Mainpat’s grass can be white with frost.
Behind these festivals is a regular cycle of four seasons, each caused by a different arrangement of pressure, winds and sunshine. What are India’s seasons, what weather does each one bring, and which local storms and winds belong to which season?
Why it matters: Prelims loves the local-wind and local-storm names (loo, mango showers, kalbaisakhi), western disturbances and the north-east monsoon. Mains asks how the seasons shape agriculture, disasters and health.
The Four Seasons
The Indian Meteorological Department recognises four seasons (ऋतुएँ). Textbooks (NCERT) describe them like this:
| Season | Months | Main control | Key weather |
|---|---|---|---|
| Cold weather season (शीत ऋतु) | December–February (from mid-November in the north) | High pressure over north-west India; dry north-east winds; westerly jet south of the Himalaya | Clear skies, cold nights, fog in the Ganga plain, cold waves; western disturbances bring rain and snow to the north-west |
| Hot weather season (ग्रीष्म ऋतु) | March–May | Sun moves north; heat low builds over north-west India | Rising temperatures, loo, dust storms, local thunderstorms (mango showers, kalbaisakhi) |
| South-west monsoon season (वर्षा ऋतु) | June–September | Monsoon trough; south-west winds | About three-quarters of the year’s rain; breaks; floods and landslides |
| Retreating monsoon / post-monsoon (शरद ऋतु / लौटता मानसून) | October–November (IMD’s post-monsoon season runs October–December) | Trough weakens and moves south; winds turn north-easterly | October heat in the north; north-east monsoon rain in Tamil Nadu; tropical cyclones on the east coast |
1. The Cold Weather Season
Temperature:
- Temperature falls from south to north. Chennai stays warm (around 24–25 °C mean in January), while the northern plains have January means well below 20 °C and cold nights.
- The Himalaya and the north-west can fall below freezing; snowfall in the western and central Himalaya.
- Places near the sea (Mumbai, Kochi) have little seasonal change: the maritime effect.
Pressure and winds: high pressure over north-west India and Central Asia. Dry north-easterly winds blow from land to sea. The Himalaya keep the coldest Siberian air out.
Western disturbances (पश्चिमी विक्षोभ):
- Low-pressure systems that originate over the Mediterranean region and move east across West Asia, steered by the subtropical westerly jet stream.
- They bring winter rain to Punjab, Haryana, Delhi and western Uttar Pradesh and snow to the western Himalaya.
- This small amount of winter rain is very valuable for the rabi crops, especially wheat.
North-east monsoon: north-east winds that pick up moisture over the Bay of Bengal give winter rain to the Tamil Nadu coast (continuing from the post-monsoon season).
Chhattisgarh in winter: cool and dry. The plains have pleasant days and cool nights; Mainpat and the Surguja–Jashpur uplands are the coldest areas and can see frost.
2. The Hot Weather Season
Temperature:
- With the sun moving north towards the Tropic of Cancer, temperatures rise first in the south (March) and then in the north (May).
- May is the hottest month in most of north and central India; maximum temperatures of 45 °C or more are common in Rajasthan, Vidarbha and the Chhattisgarh plain.
- The south stays a little cooler because of the moderating influence of the sea.
Pressure: a heat low develops over north-west India and Pakistan. This low helps pull in the monsoon later.
Local winds and storms of the hot season (very high-yield):
| Name | Region | What it is | Effect |
|---|---|---|---|
| Loo (लू) | North and north-west India (Punjab, Haryana, Rajasthan, Uttar Pradesh, Bihar) | Hot, dry, gusty westerly or north-westerly winds in the afternoons of May–June | Heatstroke, deaths in severe heat waves |
| Dust storms (आँधी) | Rajasthan, Punjab, Haryana, Uttar Pradesh | Evening storms carrying dust, often in May | Temporary relief from heat; damage to houses and power lines |
| Mango showers (आम्र वर्षा) | Kerala and coastal Karnataka | Pre-monsoon thunderstorms near the end of summer | Help the early ripening of mangoes |
| Blossom showers / cherry blossoms | Kerala and Karnataka (coffee areas) | Pre-monsoon showers | Make coffee flowers blossom |
| Nor’westers / Kalbaisakhi (काल बैसाखी) | West Bengal, Odisha, Assam | Violent evening thunderstorms with north-westerly squalls. “Kalbaisakhi” means the calamity of the month of Baisakh. In Assam they are called Bardoli Chheerha | Useful for tea, jute and rice; in Assam they are sometimes called “tea showers”. They also cause damage |
Heat waves: IMD declares a heat wave on the basis of how far the maximum temperature departs from normal, or when it crosses set thresholds. Heat waves are a recurring disaster in the hot season, and several states, including Chhattisgarh, now prepare heat action plans. India’s highest officially recorded temperature, 51.0 °C at Phalodi (Rajasthan) in May 2016, came in this season.
3. The South-West Monsoon Season
Covered in detail in Mechanism of the Indian Monsoon and Rainfall Distribution. Key points:
- Onset over Kerala about 1 June; whole country by about 8 July.
- Brings about three-quarters of India’s annual rainfall.
- Active spells and breaks; floods in Assam, Bihar and the Ganga plain; landslides in the Himalaya and the Western Ghats.
- Temperatures fall after onset, but humidity rises, so the weather is often sultry.
Chhattisgarh in the rainy season: the monsoon reaches Bastar around mid-June. Most of the state’s rain falls in June–September, the kharif paddy season. Hareli is celebrated in Sawan, once the fields are green.
4. The Retreating Monsoon Season
What happens:
- From mid-September the monsoon trough weakens and moves south; withdrawal begins in west Rajasthan (about 17 September) and ends by about 15 October.
- Skies clear in north India and winds turn north-easterly.
October heat (अक्टूबर की गर्मी): after the rains stop, the land is still wet and the sun is still strong. High temperature and high humidity make October oppressively hot and humid in north India.
North-east monsoon and Tamil Nadu:
- The Coromandel coast of Tamil Nadu and adjoining south Andhra Pradesh receive a large share of their annual rain in October–December.
- The north-east winds pick up moisture over the Bay of Bengal, and cyclonic depressions add heavy rain.
Tropical cyclones (उष्णकटिबंधीय चक्रवात):
- The post-monsoon (October–November) and pre-monsoon (April–May) periods are the main cyclone seasons.
- The Bay of Bengal produces more cyclones than the Arabian Sea; they strike the coasts of Odisha, Andhra Pradesh, Tamil Nadu and West Bengal. Deltas of the Mahanadi, Godavari, Krishna and Kaveri are especially vulnerable.
- Remnants of Bay of Bengal systems can bring heavy rain to Chhattisgarh after crossing Odisha.
The Traditional Six Seasons (षड् ऋतु)
Interview boards and the Hindi paper sometimes ask the traditional Indian seasons:
| Season | Hindu months | Approximate Gregorian months |
|---|---|---|
| Vasant (वसंत) — spring | Chaitra–Vaishakh | March–April |
| Grishma (ग्रीष्म) — summer | Jyeshtha–Ashadh | May–June |
| Varsha (वर्षा) — rainy | Shravan–Bhadrapad | July–August |
| Sharad (शरद) — autumn | Ashwin–Kartik | September–October |
| Hemant (हेमंत) — pre-winter | Margashirsha–Paush | November–December |
| Shishir (शिशिर) — winter | Magh–Phalgun | January–February |
Analysis: Seasons and Life (Mains material)
- Cropping seasons: kharif is sown with the south-west monsoon and harvested in autumn; rabi is sown in the cold season and depends on residual moisture, irrigation and western-disturbance rain; zaid is a short summer season. In Chhattisgarh, kharif paddy dominates and rabi is limited by irrigation.
- Disasters by season: cold waves and fog (winter), heat waves and nor’wester damage (summer), floods and landslides (monsoon), cyclones (post-monsoon and pre-monsoon). Disaster preparedness calendars follow this cycle.
- Health: heatstroke in summer; vector-borne diseases such as malaria and dengue after the rains; malaria remains a concern in forested Bastar after the monsoon.
- Energy and water: peak electricity demand comes in the hot season; reservoirs fill only in the monsoon, so summer water stress is common in towns.
- Changing seasons: studies report more frequent heat waves and erratic pre-monsoon storms, which affect labour productivity and crop timing.
Memory Tricks
- North / north-west: loo and dust storms.
- South-west coast (Kerala, Karnataka): mango showers and blossom (coffee) showers.
- East (Bengal, Odisha, Assam): kalbaisakhi / nor’westers; in Assam, Bardoli Chheerha, helpful for tea.
Don’t Confuse
| This | vs | That |
|---|---|---|
| Mango showers — Kerala and coastal Karnataka, help mangoes ripen | vs | Blossom showers — Kerala and Karnataka, help coffee flowers |
| Kalbaisakhi — Bengal, evening thunderstorms in Baisakh | vs | Loo — hot, dry afternoon winds of north-west India |
| Western disturbance — winter rain in the north-west, from the Mediterranean | vs | North-east monsoon — winter and post-monsoon rain on the Tamil Nadu coast |
| October heat — hot and humid north India after the retreat | vs | Heat wave — very high temperatures, mainly May–June |
| NCERT cold season — December–February | vs | IMD winter season (statistics) — January–February |
Common Mistakes
- “Mango showers occur in Bengal.” No. They occur in Kerala and coastal Karnataka. Bengal has kalbaisakhi.
- “Western disturbances are a feature of the monsoon season.” No. They are mainly a winter feature, brought by the westerly jet.
- “Tea showers” belong to Kerala. No. The term is used for nor’westers in Assam.
- “Cyclones are most frequent in July–August.” No. The main cyclone seasons are October–November and April–May.
- “The hottest month everywhere in India is June.” In most of north and central India it is May; after the monsoon arrives in June, temperatures fall.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- Winter rain in Punjab and Haryana is brought by ______ that originate over the Mediterranean region.
- Pre-monsoon showers that help the early ripening of mangoes in Kerala are called ______.
- In Assam, the nor’westers are locally called ______.
Answers
- Western disturbances.
- Mango showers.
- Bardoli Chheerha.
Level 2: Prelims MCQs
Q1. Consider the following statements:
- Western disturbances bring winter rain to north-west India and are beneficial for the rabi crop.
- The “October heat” in north India is caused by high temperature combined with high humidity after the monsoon withdraws.
- The Coromandel coast receives most of its annual rainfall during June–September.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
Q2. Match List I (Local phenomenon) with List II (Region):
| List I | List II |
|---|---|
| A. Loo | 1. Kerala and coastal Karnataka |
| B. Mango showers | 2. West Bengal |
| C. Kalbaisakhi | 3. Assam |
| D. Bardoli Chheerha | 4. North-west India |
- (a) A-4, B-1, C-2, D-3
- (b) A-4, B-2, C-1, D-3
- (c) A-1, B-4, C-2, D-3
- (d) A-4, B-1, C-3, D-2
Answer and explanation
Q3. Which of the following periods are the main tropical cyclone seasons over the north Indian Ocean?
- (a) January–February and July–August
- (b) April–May and October–November
- (c) June–July only
- (d) December–February only
Answer and explanation
Q4. In the traditional Indian calendar, the season “Hemant” corresponds roughly to:
- (a) March–April
- (b) July–August
- (c) November–December
- (d) January–February
Answer and explanation
Level 3: Mains Answer Writing
Q1. (150–200 words) Describe the weather conditions of the hot weather season in India. Explain the local storms of this season and their economic significance.
Model answer outline
- Intro: March–May; the sun moves north, a heat low forms over north-west India and prepares the ground for the monsoon.
- Body:
- Temperatures rise from south to north; May is hottest in north and central India (45 °C or more in Rajasthan and the Chhattisgarh plain).
- Loo and dust storms in the north-west; heat waves and health risks.
- Mango showers (Kerala, coastal Karnataka) help mangoes; blossom showers help coffee.
- Kalbaisakhi / nor’westers in Bengal, Odisha and Assam (Bardoli Chheerha) help tea, jute and rice, but damage houses and crops.
- Chhattisgarh angle: extreme May heat in Raipur–Bilaspur affects labour, power demand and water supply; heat action plans are a response.
- Conclusion: the hot season is both a hazard and a necessary precursor to the monsoon.
Q2. (60 words) What are western disturbances? Why are they important for Indian agriculture?
Model answer outline
- Low-pressure systems originating over the Mediterranean, carried east by the subtropical westerly jet in winter.
- Bring rain to north-west India and snow to the western Himalaya.
- Rain supports rabi wheat; snow feeds Himalayan rivers in summer. Unseasonal or very strong disturbances can also damage standing crops.
Quick Revision Table
| Fact | Detail |
|---|---|
| Four seasons | Cold (Dec–Feb), hot (Mar–May), south-west monsoon (Jun–Sep), retreating monsoon (Oct–Nov) |
| IMD statistical seasons | Winter Jan–Feb; pre-monsoon Mar–May; SW monsoon Jun–Sep; post-monsoon Oct–Dec |
| Western disturbances | Mediterranean origin; westerly jet; winter rain in the north-west; good for wheat |
| Loo | Hot, dry afternoon winds; north-west India; May–June |
| Mango showers | Kerala and coastal Karnataka |
| Blossom showers | Coffee areas of Kerala and Karnataka |
| Kalbaisakhi | Nor’westers of Bengal; Bardoli Chheerha in Assam; tea showers |
| Highest recorded temperature | 51.0 °C, Phalodi (Rajasthan), May 2016 |
| October heat | Hot, humid north India after withdrawal |
| North-east monsoon | Tamil Nadu coast, October–December |
| Cyclone seasons | April–May and October–November; Bay of Bengal more active |
| Six traditional seasons | Vasant, Grishma, Varsha, Sharad, Hemant, Shishir |
Key Takeaways
- India has four seasons, each tied to the position of the sun, the ITCZ and the jet streams.
- Western disturbances (winter, north-west) help rabi wheat; the north-east monsoon waters Tamil Nadu in October–December.
- Hot-season storms have regional names: loo (north-west), mango and blossom showers (south-west coast), kalbaisakhi and Bardoli Chheerha (east and north-east).
- Cyclones peak in the transition seasons, mainly from the Bay of Bengal.
- In Chhattisgarh, May heat, June–September rain and a cool dry winter frame the kharif-dominated farm year.
What’s Next
- Rainfall Distribution in India — where and how reliably the rain falls
- El Niño, La Niña and the Indian Ocean Dipole — year-to-year swings
- Agriculture in India — kharif, rabi and zaid seasons
- Environment and Ecology — heat waves, cyclones and climate change
- Festivals and Traditions of Chhattisgarh — Hareli, Cherchera and the farm calendar