The Four Colours of Your Commute
The IMD uses a simple, four-colour system to communicate the severity of expected rainfall and its potential impact. These alerts—Green, Yellow, Orange, and Red—are designed to simplify complex weather data, helping you quickly assess the risk before
you step out. They are issued for districts and cities and are valid for up to five days, giving you a window to prepare. Understanding what each colour means is the first step to a smarter, safer journey during the rainy season.
Green Alert: No Warning
A Green alert means “All Clear.” When this is active, weather conditions are considered normal with no significant rainfall expected that would disrupt your day. It generally indicates light showers or dry weather. While you can proceed with your commute as planned, it's always wise to keep an eye on the forecast, as conditions can change rapidly, especially during the monsoon. A Green alert essentially means no advisory is necessary at that moment.
Yellow Alert: Be Aware
A Yellow alert is a call to “Watch” or “Be Aware.” It signifies that moderately bad weather is possible and could interfere with daily activities. For rainfall, this typically means a forecast of moderate to heavy rain (between 64.5 mm and 115.5 mm in 24 hours). While widespread disruption isn't expected, you should anticipate some travel delays. Practical steps include carrying an umbrella, allowing extra travel time, checking traffic updates before you leave, and being cautious in low-lying areas that are prone to waterlogging.
Orange Alert: Be Prepared
When you see an Orange alert, it’s time to “Be Prepared.” This indicates a forecast of heavy to very heavy rainfall (between 115.6 mm and 204.4 mm in 24 hours), with a high likelihood of disruptions. Expect traffic congestion, waterlogged streets, and potential interruptions to rail, road, and power services. If an Orange alert is issued, seriously consider if your travel is necessary. If you must commute, avoid known waterlogging spots, keep emergency supplies handy, and inform your workplace about potential delays. This is a serious warning that demands proactive measures.
Red Alert: Take Action
A Red alert is the highest level of warning and means “Take Action.” It is issued for extremely heavy rainfall (exceeding 204.5 mm in 24 hours) when severe weather is expected to cause significant risk to life and property. Widespread flooding, damage to infrastructure, and major travel and power disruptions are highly likely. During a Red alert, authorities advise citizens to avoid all non-essential travel and stay indoors for safety. Schools and offices may be closed, so it is crucial to follow instructions from local disaster management authorities.
Your Digital Weather Toolkit
Beyond just the colour codes, the IMD provides powerful digital tools for real-time information. The 'Mausam' app, available for both Android and iOS, gives you current weather data, forecasts, and warnings for over 450 cities. A key feature for commuters is the 'Nowcast' service, which provides district-wise warnings for intense weather events expected within the next few hours. These short-range forecasts are invaluable for making last-minute decisions about your commute. Other apps like 'Damini' provide lightning alerts, adding another layer of safety.
