How Weather Forecasts Are Made
A weather forecast is a scientific prediction of what the atmosphere will do next. It is built in four main steps:
Observe
Thousands of weather stations, balloons, ships, aircraft, radars and satellites measure temperature, wind, humidity and pressure every hour.
Compute
The data is fed into supercomputers that run weather models – physics equations that simulate how air, heat and moisture move.
Interpret
Meteorologists compare several models, check them against local knowledge and decide the most likely outcome.
Publish
The final forecast is shared as temperatures, rain chances and warnings – like the forecast on our home page.
Tip: Forecasts for the next 3 days are highly reliable. Beyond 7 days, treat them as a trend and check again closer to the date.
Types of Clouds & What They Mean
Clouds are one of the easiest ways to read the sky. Here are the most common ones:
Cumulus Fair weather
Puffy, white, cotton-like clouds with flat bottoms. They usually mean pleasant, dry weather.
Stratus Dull & grey
Flat, grey layers that cover the whole sky like a blanket. Expect a dull day, mist or light drizzle.
Cirrus Change ahead
Thin, wispy, feather-like clouds high in the sky. Often a sign that the weather will change in a day or two.
Nimbostratus Steady rain
Thick, dark grey clouds that block the sun. They bring steady, continuous rain or snow.
Cumulonimbus Storms
Huge, towering storm clouds with an anvil-shaped top. They bring thunder, lightning, heavy rain and sometimes hail.
Through the year
Seasons & What to Expect
In India, the year is generally divided into four main weather seasons.
Summer
March – May
Hot and dry with temperatures often above 40°C in the plains. Heat waves are common in May. Stay hydrated and avoid the afternoon sun.
Monsoon
June – September
The south-west monsoon brings most of the year's rainfall. Expect humid days, heavy showers, waterlogging and occasional floods.
Post-Monsoon
October – November
Skies clear up and temperatures become pleasant. The east coast can still get rain and cyclones from the Bay of Bengal.
Winter
December – February
Cool to cold, especially in the north, with dense morning fog and cold waves. Hill areas may see snowfall.
Measuring the sky
Instruments Used to Measure Weather
Thermometer
Measures air temperature in °C or °F.
Barometer
Measures air pressure – useful for predicting rain or clear skies.
Anemometer
Measures wind speed using spinning cups.
Rain Gauge
Collects and measures the amount of rainfall in millimetres.
Hygrometer
Measures humidity, the amount of moisture in the air.
Satellite & Radar
Track clouds, storms and rainfall from space and the ground.
Natural Signs of Changing Weather
Long before apps, people read the sky. Some of these old signs still hold true:
- Red sky at night
Often means dry, settled weather the next day. A red sky in the morning can signal rain later.
- Morning dew or fog
Usually points to a clear, calm day ahead.
- Sudden cool wind
On a hot day, it often arrives just before a thunderstorm.
- Birds flying low
Falling air pressure before rain keeps insects – and the birds that eat them – closer to the ground.
- Ring around the moon
A halo caused by high cirrus clouds, often a sign that rain is coming within a day or two.
Check the weather for your city
Current conditions, hourly updates and a 10 day forecast.