The India Meteorological Department (IMD) plays a critical role in safeguarding lives and property in cyclone-prone regions by issuing timely and clear weather warnings. Among its most significant tools is the color-coded weather warning system, which translates complex meteorological data into actionable alerts for the public, disaster management authorities, and local administrations. This system is especially vital in areas vulnerable to cyclonic disturbances, where rapid response and preparedness can mean the difference between safety and catastrophe.

Purpose and Importance of Colour-Coded Warnings

The IMD’s colour-coded warning system is designed to:

• Communicate the severity and likelihood of impending weather events, particularly cyclones.
• Guide authorities and the public in taking appropriate preparedness and response measures.
• Reduce loss of life, injury, and property damage by ensuring timely dissemination of information.

These warnings are updated daily and are not exclusive to cyclones—they are also used for other severe weather events such as heavy rainfall, floods, and snowstorms

The Four Colour Codes: Meaning and Actions

The IMD’s system uses four distinct colour codes: Green, Yellow, Orange, and Red. Each colour represents a specific level of threat and prescribes corresponding actions for authorities and the public.

1. Green – ‘All is Well’

• Meaning: No adverse weather conditions are expected. This is a signal of normalcy, with no threats from cyclonic activity or other severe weather events.
• Action: No advisory is issued. Daily activities can continue as usual.

Application: In cyclone-prone areas, a green warning means there is no cyclone formation or threat on the horizon. It reassures the public and authorities that no special precautions are needed.

2. Yellow – ‘Be Aware’

• Meaning: Weather conditions could become potentially dangerous, with the likelihood of severely bad weather spanning several days. This stage often signals the early formation or approach of a cyclone, or the possibility of adverse weather that could disrupt daily life.
• Action: Be alert and stay updated with the latest forecasts. Prepare for possible disruptions to daily activities. No immediate action is required, but readiness is advised.

Application: For cyclones, a yellow warning may be issued when a depression or low-pressure area forms over the sea, indicating a cyclone could develop. Residents and authorities should monitor updates and prepare for changes.

3. Orange – ‘Be Prepared’

• Meaning: There is an increased likelihood of extremely severe weather, including strong winds, heavy rainfall, and the potential for significant disruption and damage. This stage often indicates that a cyclone is expected to impact the area within a short period (typically 24–48 hours).
• Action: Prepare for severe weather. Follow advice from local authorities. Secure property, stock emergency supplies, and be ready for evacuation if necessary.

Application: In cyclone-prone areas, an orange alert is a call to action for disaster management agencies to mobilize resources, for hospitals and emergency services to be on standby, and for the public to finalize preparations such as securing homes and gathering essential supplies.

4. Red – ‘Take Action’

• Meaning: Extremely severe weather is imminent or already occurring, posing a high risk to life and property. This is the highest level of warning, indicating that the cyclone is about to make landfall or is already affecting the area.
• Action: Take immediate action to ensure safety. Follow evacuation orders, seek shelter, and avoid all travel unless absolutely necessary. Disaster management teams are fully deployed, and emergency protocols are activated.

Application: A red warning during a cyclone means the event is certain to cause widespread disruption—travel, power, and communication networks are likely to be severely affected. Authorities may enforce mandatory evacuations, and all emergency response mechanisms are fully operational.

Decision-Making Criteria for Colour Codes

The IMD determines the appropriate colour code based on:

• Meteorological data (wind speed, pressure, rainfall, storm surge projections).
• Hydrological factors (likelihood of flooding, river levels).
• Geophysical and vulnerability assessments (population density, infrastructure at risk).

This multi-factor approach ensures that warnings are both timely and context-sensitive, maximizing their effectiveness in reducing harm.

Case Study: Application During Cyclone Events

During major cyclonic events, such as Cyclone Tauktae (2021), the IMD’s colour-coded warnings played a pivotal role:

• Yellow warning was first issued as the cyclone formed, alerting people to monitor updates.
• Orange warning was given as the cyclone intensified and approached the coast, prompting preparations and resource mobilization.
• Red warning was issued when landfall was imminent, triggering evacuations and full-scale emergency response.

Broader Relevance and Impact

While the colour-coded system is universally applied for all severe weather events, its importance is heightened in cyclone-prone coastal regions. The clarity and simplicity of the colour codes:

• Enable quick understanding and response by the general public, including those with limited technical knowledge.
• Provide a standardized framework for inter-agency coordination, ensuring that disaster management and emergency services act in concert.
• Help minimize panic by offering clear, graduated guidance rather than sudden, ambiguous alerts.

The IMD’s colour-coded weather warning system is a cornerstone of India’s disaster risk reduction strategy in cyclone-prone areas. By translating complex meteorological forecasts into simple, actionable alerts—Green (All is well), Yellow (Be aware), Orange (Be prepared), and Red (Take action)—the IMD empowers both authorities and the public to respond appropriately to varying levels of cyclone threat. This system has proven effective in saving lives, reducing property damage, and enhancing community resilience against one of the most formidable natural hazards faced by India’s coastal regions.

there are several recent examples of successful evacuations in India that were prompted by timely warnings from the India Meteorological Department (IMD):

• Cyclone Fani (2019, Odisha): IMD’s improved warning system and repeated alerts enabled authorities to evacuate over 11.5 lakh (1.15 million) people from Odisha, Andhra Pradesh, and West Bengal before Cyclone Fani made landfall. This large-scale evacuation, coordinated with the National Disaster Response Force (NDRF) and local agencies, drastically reduced casualties compared to previous cyclones. The death toll was limited to single digits, a significant achievement given the cyclone’s severity. The success was attributed to accurate forecasts, early warnings, and effective last-mile communication, earning praise from both national and international organizations.
• Gujarat Rains (August 2024): In response to IMD’s orange and red alerts for heavy rainfall and flooding in Gujarat, authorities evacuated over 23,870 people from vulnerable districts such as Vadodara, Panchmahals, Navsari, Valsad, Bharuch, Kheda, and Botad. The IMD’s warnings prompted swift action by the state government, NDRF, and SDRF teams, ensuring that thousands were moved to safety before river levels rose dangerously and low-lying areas were inundated.
• Cyclones Hudhud (2014), Phailin (2013), Amphan (2020), and Mocha (2023): These cyclones also saw successful mass evacuations in affected coastal states, thanks to IMD’s accurate and timely warnings. For example, ahead of Cyclone Hudhud, up to 4 lakh (400,000) people were evacuated in Odisha alone, which was recognized by the UN Office for Disaster Risk Reduction as a model for disaster response.

These examples highlight the effectiveness of IMD’s colour-coded warning system and improved forecasting capabilities in facilitating timely evacuations, minimizing casualties, and protecting lives and property during severe cyclonic and weather events.