India Meteorological Department

IMD Full Form in English, letter by letter

IMD stands for India Meteorological Department, the government body that issues weather forecasts, monsoon outlooks and cyclone warnings for India.

IMD Full Form in Indian Languages

IMD is the abbreviation for the India Meteorological Department, the government body behind the monsoon forecast and cyclone warnings you see on the news.

What IMD does

The India Meteorological Department is India's national weather service. It observes the atmosphere, issues forecasts and warnings, and supports agriculture, aviation and shipping.

It works under the Ministry of Earth Sciences and is headquartered in New Delhi. When a news channel says a depression over the Bay of Bengal will turn into a cyclonic storm, that call is usually IMD's.

Its area of responsibility includes the Indian landmass and the surrounding seas, including the Arabian Sea and the Bay of Bengal, where most destructive weather around India forms. It also acts as a Regional Specialised Meteorological Centre for tropical cyclones in the North Indian Ocean.

Many private weather apps in India draw on IMD data. Railways, the NDRF and state disaster authorities act on IMD bulletins.

An older history than most government departments

IMD was set up in 1875, after devastating cyclones on the east coast in the 1860s, including the Calcutta cyclone of 1864, and a series of failed monsoons. That makes it one of the oldest weather services in Asia.

For most of the 20th century it sat under different central ministries. It moved under the Ministry of Earth Sciences when that ministry was formed in 2006, which is why older books describe it differently.

Some hill stations and coastal observatories hold records going back more than a century, which gives Indian monsoon research an unusually long baseline.

The monsoon forecast everyone waits for

IMD's best-known product is the southwest monsoon forecast. The normal onset date over Kerala is 1 June, give or take about a week, and the monsoon normally covers the whole country by around 8 July. Actual dates vary from year to year.

In April IMD issues its long-range forecast, expressed as a percentage of the long period average of about 87 cm (868.6 mm) for the June to September season. A forecast of 96 to 104 per cent of that average is called normal. A second forecast follows around the end of May.

Through the season it issues extended-range outlooks, district-level agromet advisories and heat-wave warnings, delivered to farmers through state agriculture departments, Krishi Vigyan Kendras and SMS alerts.

Satellite data, including images from ISRO's INSAT series, radars and automatic weather stations feed these forecasts.

A practical tip for farmers and students: read the forecast as a probability, not a promise. A statement like "heavy rainfall likely at isolated places" means some districts will get it and others will not. The district-wise bulletin and the nowcast, which covers the next three hours, are more useful for planning a trip or a sowing day than the national summary.

Cyclone bulletins and colour codes

IMD uses four colours in its warnings: green means no action is needed, yellow means be aware and keep watching, orange means be prepared, and red means take action.

Cyclonic systems are graded by wind speed, from a depression to a deep depression, a cyclonic storm, a severe cyclonic storm and beyond. Each stage prompts a different response from state control rooms and the NDRF.

Names come from a rotating list agreed by the countries of the WMO/ESCAP Panel on Tropical Cyclones, which is how names such as Biparjoy and Dana were assigned to storms in the North Indian Ocean.

Heat waves have their own criteria. IMD declares one when the maximum temperature crosses a set threshold, which differs for plains, hills and coastal areas, and when it is well above the normal for the place. That is why a city can be under an alert at a temperature that would be ordinary elsewhere.

Aviation, daily forecasts and how to check them

IMD also issues aerodrome warnings and fog advisories for airports, which is why winter flight operations at Delhi depend on its visibility bulletins. Earthquake monitoring is done by the National Centre for Seismology, which was part of IMD earlier and now works separately under the same ministry.

For personal use, the Mausam app and the IMD website carry current warnings, radar images and station readings. They are more reliable than forwarded messages claiming a super-cyclone is coming.

Students meet IMD in general knowledge papers and school geography, where questions usually ask for the full form, the year of founding or the ministry it works under.

IMD sits behind most weather alerts in India, from the April monsoon outlook to a red warning for a landfalling cyclone. During a warning, follow its official bulletins and your state disaster authority.

IMD Full Form: Common Questions