The IMD's Colour-Coded System
The India Meteorological Department (IMD) is the government's official agency for weather forecasting. To make its warnings easy to understand for the public and authorities, it uses a colour-coded system. These alerts—Green, Yellow, Orange, and Red—are
designed to inform everyone about the expected intensity of a weather event and its potential impact. This system isn't just for rain; it also covers heatwaves, cold waves, and cyclones, but during the monsoon, it's an essential tool for anticipating travel disruptions. The alerts are issued based on the probability of a weather event and the damage it might cause, allowing travellers and residents to prepare accordingly.
Green Alert: No Warning
A Green alert is the most welcome sign for any traveller. It means that weather conditions are normal and no significant adverse weather is expected. When a Green alert is in effect, you can proceed with your travel and daily activities as planned without any weather-related restrictions. It essentially signals that 'all is well,' and there's no need for a specific weather advisory. It’s the ideal condition for sightseeing, road trips, and exploring the rain-washed beauty of Indian cities and landscapes.
Yellow Alert: Be Aware
A Yellow alert serves as the first level of warning and means you should 'be aware'. It indicates that weather conditions could worsen over the next few days and advises the public to stay updated. For rainfall, a Yellow alert is typically issued when 64.5 mm to 115.5 mm of rain is expected within a 24-hour period. While widespread disruption isn't usually anticipated, this level of rain can cause some localised waterlogging and minor travel delays. If you see a Yellow alert for your destination, it's wise to allow for extra travel time and keep a close eye on weather updates.
Orange Alert: Be Prepared
The Orange alert is a more serious warning that signals you to 'be prepared'. It is issued when extremely bad weather is likely, with a high probability of disruptions. In the context of monsoon rain, this alert corresponds to an expected rainfall of 115.6 mm to 204.4 mm in 24 hours. This amount of rain can lead to significant traffic congestion, localised flooding, and delays or cancellations of road, rail, and air travel. Authorities advise residents to secure outdoor items, prepare for potential power outages, and avoid unnecessary travel if conditions deteriorate.
Red Alert: Take Action
A Red alert is the highest level of warning and means it's time to 'take action'. This alert is issued when extremely severe weather is imminent, posing a significant threat to life and property. For rainfall, this means a forecast of over 204.5 mm in 24 hours, which can cause severe flooding and landslides. During a Red alert, major disruptions to transport and power are highly likely. Authorities will advise the public to avoid all non-essential travel, stay indoors, and follow their instructions, which may include evacuation from vulnerable, low-lying areas. Personal safety is the absolute priority.
Practical Tips for Monsoon Travel
Beyond understanding the alerts, practical preparation is crucial. Always check the weather forecast for your destination before and during your trip. Pack quick-drying clothes, waterproof footwear, and a reliable raincoat. Keep your essential electronics in waterproof bags. During heavy rain, especially under Orange or Red alerts, avoid driving at night or through flooded roads, as it's difficult to gauge water depth. In hilly regions like the Himalayas or Western Ghats, be extremely cautious about the risk of landslides. It's also wise to keep your itinerary flexible, with buffer days to account for potential delays.
