IMD uses four colours: green means no warning, yellow means be updated, orange means be prepared, and red means take action. For cyclones, warnings come in stages: pre-cyclone watch, cyclone alert about 48 hours before, cyclone warning about 24 hours before, and a post-landfall outlook. Cyclone Murasu in November 2026 showed all of them.
Updated 3 November 2026
Quick facts
| Item | Details |
|---|---|
| Official portal | mausam.imd.gov.in for warnings; sachet.ndma.gov.in for alerts by area |
| Helpline | 112 for emergencies; 1070 state and 1077 district disaster control rooms in most states |
| Fee | Free. All IMD warnings and the Mausam and Sachet apps are free |
| Deadline | Act on a red alert right away; orange means get ready within the day |
| Documents | Keep Aadhaar, ration card, bank passbook and land papers in a waterproof bag |
| Latest case | Severe Cyclonic Storm Murasu, landfall near Ongole, Andhra Pradesh, from about 1 am on 3 November 2026 |
What do the four IMD colours mean?
The India Meteorological Department (IMD) puts a colour on every district in its forecast. It's a simple traffic-light idea, but people mix them up all the time.
| Colour | What IMD means | What you should do |
|---|---|---|
| Green | No warning | Nothing special. Carry on |
| Yellow | Be updated | Weather could turn bad. Keep checking forecasts |
| Orange | Be prepared | Severe weather is likely. Plan for power cuts, stock water, avoid travel if you can |
| Red | Take action | Extremely bad weather is expected. Follow official orders, move to safety if told to |
A red alert is not "maximum rain". It's IMD saying the impact could be serious enough that the district administration needs to act, like shutting schools, stopping fishing or moving people out of low-lying areas.
How does IMD decide between heavy, very heavy and extremely heavy rain?
These words have exact numbers behind them. IMD measures rain over 24 hours at a station:
| IMD term | Rain in 24 hours |
|---|---|
| Heavy | 64.5 mm to 115.5 mm |
| Very heavy | 115.6 mm to 204.4 mm |
| Extremely heavy | 204.5 mm or more |
So when you read "very heavy rain at isolated places", it means one or a few spots in the district may get between 115.6 mm and 204.4 mm. That's enough to flood roads and fill drains in most Indian cities.
How are cyclones graded by IMD?
IMD names the category based on the maximum sustained wind speed (the average over a few minutes, not the gusts):
| Category | Wind speed |
|---|---|
| Depression | 31 to 49 km/h |
| Deep Depression | 50 to 61 km/h |
| Cyclonic Storm | 62 to 88 km/h |
| Severe Cyclonic Storm | 89 to 117 km/h |
| Very Severe Cyclonic Storm | 118 to 165 km/h |
| Extremely Severe Cyclonic Storm | 166 to 220 km/h |
| Super Cyclonic Storm | 221 km/h or more |
A system gets a name only once it becomes a Cyclonic Storm. The names come from a list drawn up in advance by countries around the Bay of Bengal and Arabian Sea, and they're used in order.
What are the four stages of a cyclone warning?
This is the part most people don't know. IMD doesn't just say "cyclone coming". It warns in stages:
1. Pre-cyclone watch. Issued when a system is likely to become a cyclone and may affect the coast. Usually about 72 hours ahead. It's mostly for officials to start preparing.
2. Cyclone alert. Issued about 48 hours before bad weather starts on the coast. Fishermen are told to return. This is when you should start preparing at home.
3. Cyclone warning. Issued about 24 hours before. It names the districts likely to be hit, the expected wind, rain and storm surge. Evacuation usually starts here.
4. Post-landfall outlook. Issued about 12 hours before landfall. It's about what happens inland after the storm crosses the coast, since heavy rain often continues for a day or two.
Warnings for fishermen are separate and often stricter. When IMD says "fishermen are advised not to venture into sea", it's a firm instruction, and coastal districts usually enforce it.
What happened with Cyclone Murasu in November 2026?
Cyclone Murasu was a Severe Cyclonic Storm in the Bay of Bengal. As per reports quoting IMD, its landfall process began around 1 am on 3 November 2026 near Kothapatnam, close to Ongole in Prakasam district of Andhra Pradesh. Wind speeds were around 100 to 110 km/h, gusting to 120 km/h.
IMD warned of a storm surge of about 1.5 to 2 metres above the astronomical tide, mainly over Bapatla, Krishna and Prakasam. Red alerts on 3 November 2026 were reported for Eluru, West Godavari and Alluri Sitharama Raju in Andhra Pradesh, and Nalgonda and Nagarkurnool in Telangana.
The AP government also opened a WhatsApp service on its Mana Mitra number (9552300009), with a "Murasu Cyclone Issues" option under Services, so people could report problems. If you were affected, our guide on cyclone relief and compensation in Andhra Pradesh explains how house, crop and boat damage claims usually work.
What is a storm surge, and why is it so dangerous?
A storm surge is the sea level pushed up by the cyclone's winds and low pressure. It floods coastal land from the sea side. A 2 metre surge on top of a high tide can push seawater far inland in flat areas. Most cyclone deaths in history were from surges, not wind. That's why coastal evacuation orders should never be ignored.
Where can I get these alerts on my phone?
You don't need to wait for TV. Use these free official tools:
• Mausam app (IMD): district-wise colour-coded warnings, radar and forecast
• Sachet app (NDMA): alerts for your exact location, in many Indian languages
• Cell broadcast: emergency messages pushed to all phones in an area. Our post on how cell broadcast alerts work explains the loud alarm tone
• Damini app: lightning warnings
• IMD website: mausam.imd.gov.in has the latest bulletins
What should I do at each alert level?
On yellow: check the forecast twice a day. Charge phones and power banks.
On orange: ☐ Stock drinking water and dry food for 2 to 3 days ☐ Keep torches, candles and a battery radio ☐ Put documents in a waterproof bag ☐ Tie down loose roof sheets and move things off the balcony ☐ Note your district control room number (often 1077)
On red:
• Follow district orders. If told to move to a cyclone shelter, go
• Stay indoors once wind picks up
• Switch off mains power if water enters your home
• Don't go out "to see" the storm, even if it looks calm. The eye passing over can give a false break
Final reminder
Colours tell you how worried to be. Stages tell you how much time you have. When a cyclone warning names your district, that's roughly a day's notice. Use it. Save 112, 1070 and 1077, keep the Sachet app on, and keep an eye on your local MLA's and district office updates. You can find your representatives on NetaSampark.
Frequently asked questions
What does an IMD red alert mean?
It means "take action". Very severe weather is expected and authorities may order school closures or evacuation.
What is the difference between orange and yellow alerts?
Yellow is "be updated" and orange is "be prepared". Orange means severe weather is likely, so start getting ready.
How much rain is "very heavy" as per IMD?
115.6 mm to 204.4 mm in 24 hours.
What wind speed makes a Severe Cyclonic Storm?
89 to 117 km/h of maximum sustained wind.
How early does IMD warn before a cyclone hits?
Cyclone alert about 48 hours before bad weather starts, and cyclone warning about 24 hours before.
Which app gives official disaster alerts in India?
NDMA's Sachet app and IMD's Mausam app. Both are free.
Sources
• India Meteorological Department
• National Disaster Management Authority
• Sachet: NDMA common alerting protocol portal
• Cyclone warning services, IMD Regional Specialised Meteorological Centre