Delhi records hottest April day in 5yrs; heatwave alert issued
What's the story
The India Meteorological Department (IMD) has issued an orange alert for Delhi warning of severe heatwave conditions across the city on Sunday. The warning came after Delhi witnessed its hottest April day in five years on Saturday, with a temperature of 42.4 degrees Celsius, according to the IMD. Before this, Delhi's highest maximum temperature for April—43.2 degrees Celsius—was recorded on April 21, 2017.
Context
Why does this story matter?
The meteorological department has issued a severe heatwave warning and urged people to exercise caution. Dehydration, fainting, heat cramps, exhaustion, and heat strokes can occur due to an extreme heatwave. As a result, it is strongly advised that everyone, especially the most susceptible categories of people—such as newborns, the elderly, and individuals with chronic illnesses—take extra precautions and minimize heat exposure.
Details
Delhi's highest April temperature in 72 years: IMD
To note, the highest-ever maximum temperature registered by Delhi for April was 45.6 degrees Celsius, which was recorded back on April 29, 1941. Issuing the warning, the IMD has also highlighted that on Saturday, the national capital witnessed such a high maximum temperature in the first half of the month for the first time in 72 years.
Other cities
Temperatures recorded by Delhi's neighboring cities
Earlier on Friday, the maximum temperature recorded at Delhi's base station—Safdarjung Observatory—stood at 41.6 degrees Celsius. Meanwhile, the neighboring Gurugram saw a maximum temperature of 44.5 degrees Celsius on Saturday—10 degrees above the average and quite close to Gurugram's all-time high maximum temperature of 44.8 degrees Celsius recorded on April 28, 1979. Haryana's Faridabad on Saturday witnessed a maximum temperature of 45.2 degrees Celsius.
Prediction
What is IMD's prediction for April?
Last week, the IMD had predicted above-normal maximum temperatures throughout the northwest and central India, as well as areas of the northeast, in April. According to IMD Director-General Mrutyunjay Mohapatra, normal to below-average maximum temperatures are predicted across the south peninsula, many sections of the eastern regions of the nation, and the neighboring territories of the northeast.
Color-coded system
What is the meaning of colors used?
According to the Indian Meteorological Department, "color codes are used in weather warnings for bringing out the severity of the weather phenomena expected." The IMD uses a four color-coded system for issuing weather-related warnings. They include green (no action needed); yellow (watch and stay updated); orange (be prepared); and red (take action).
Forecast scheme
How is the color forecast decided?
The IMD says colors are assigned to certain weather scenarios as per a five-day forecast method. A particular matrix is followed to analyze the probability of occurrence of an event and its impact. However, the assessment of the color codes for "impact-based warning" comprises several meteorological factors and geophysical factors, among others, "which may interact with each other to determine the impact and risk."