A city in western India has suffered through the country's highest recorded temperature - a scorching 51C (123.8F).
The record was set in the city of Phalodi, in the western state of Rajasthan. India's meteorological department said the previous high was 50.6C (123 F), reached in 1956 in the city of Alwar, also in Rajasthan.
Authorities have issued a severe heatwave alert for the next two days in the western states of Gujarat and Rajasthan and parts of the central state of Madhya Pradesh. That means the areas can expect temperatures of 47C (116.6F) or more.
The main summer months - April, May and June - are extremely hot across most parts of India before monsoon rains and cool temperatures arrive.
The monsoon hits southern India in the first week of June and covers the rest of the country within a month.
This year - as temperatures hit new highs - the monsoon is especially eagerly awaited as several parts of the country are reeling under a drought brought on by two years of weak rains.
The prolonged heatwave this year has already killed hundreds and destroyed crops in more than 13 states, impacting hundreds of millions of Indians.
Hundreds of farmers are reported to have killed themselves across the country and tens of thousands of small farmers have been forced to abandon their farmland and live in squalor in urban slums to earn a living.
Rivers, lakes and dams have dried up in many parts of the western states of Rajasthan, Maharashtra and Gujarat, and officials say overall groundwater reservoirs are severely depleted.
In some areas, the situation is so bad the government has sent in water by train for emergency relief.
Clare Nullis, a spokeswoman for the World Meteorological Organisation, said experts expect this year's monsoon will bring more rain than normal, which would be good news for the drought-stricken regions.
"Obviously the monsoon hasn't yet started. The intervening weeks will be quite serious. But I understand the Indian government is actually taking quite serious measures to address this," she said.
But she expressed alarm after scientists recorded the 12th global monthly heat record in a row.
The data from the US National Oceanic and Atmospheric Administration confirmed earlier readings taken by Nasa and the Japan Meteorological Agency. They showed that Earth's average temperature in April was 1.1C higher than the 20th-century average.
Ms Nullis said: "What's particularly concerning is the margin at which these records are being broken. They are not being broken, they are being smashed, and on a fairly consistent basis."
She told reporters in Geneva that while the records set last year were already alarming, "the heat that we're seeing in 2016 makes 2015 pale by comparison".