NEW DELHI/MEXICO CITY — Extreme heat in many parts of the world has left millions of people in sweltering temperatures, and has strained energy grids.

South Asia, Mexico, Central America and the southern part of the United States, in particular, have been hit by intense heat.

South Asia is experiencing extreme weather conditions, with at least nine killed due to a suspected heat stroke in India's west, while neighboring states are likely to be hit by a cyclone in a couple of days.

Extreme temperatures throughout Asia last month were made worse most likely as a result of human-driven climate change, a team of international scientists said.

India's summer temperatures often peak in May, but scientists have predicted more heat wave days than usual this year, largely caused by fewer non-monsoon thunder showers and an active but weakening dry El Nino weather phenomenon.

At least nine deaths in Rajasthan in India's west were suspected to have resulted from people falling sick in the sweltering heat, local media said.

In neighboring Pakistan, the climate change ministry said about 26 districts in the country were boiling under a severe heat wave as of Thursday, with the current spell of sizzling temperatures likely to last until the end of May.

Half of Pakistan's students will be shut out of schools for a week as the nation takes crisis measures to lessen the effects of a series of heat waves, officials said on Thursday.

Some 26 million students will be out of lessons from Saturday in Punjab, Pakistan's most populous province, which has ordered schools to close for the summer break one week early because of the soaring temperatures.

Pakistan's meteorological office has forecast three heat waves — one already underway and two more set to hit in early and late June.

Record levels

The extreme heat smothering much of Mexico has killed dozens of people across multiple states over recent weeks, the country's health ministry said in a report published on Thursday, with hotter temperatures forecast for coming days.

Mexico has been reeling from a high-pressure weather phenomenon known as a "heat dome", which has trapped hot air over much of the country, creating record-breaking temperatures that have surpassed 45 C in some places.

Heat-related causes killed 22 people between May 12 and 21, according to preliminary figures shared by Mexico's health ministry.

The 10-day period overlapped with the second and third heat waves out of five forecasts for March to July by the country's top weather agencies. The third heat wave is ongoing.

The high temperatures are stretching across the Gulf of Mexico into parts of the United States, including Texas and Florida. The heat comes as thousands of people in Texas remain without power after thunderstorms hammered parts of the state last week.

Shawn Bhatti, a meteorologist at the US National Weather Service forecast office in Miami, said southerly winds from the tropics transported warm, moist air northward from the equator, which contributed to the unusually warm conditions.

South Florida has been hotter than normal. Miami International Airport recorded a daily high of 35.6 C on May 19. That surpassed the temperatures of 30 C that Miami normally sees this time of the year.

A heat advisory issued by the NWS was in effect for parts of Texas on Thursday. Temperatures along the Rio Grande were expected to rise to 43.9 C and 35 C in the Davis and Chinati mountains.

Experts said the heat event raises concerns about ocean water temperatures and their influence on the upcoming Atlantic hurricane season.

Meanwhile, Bulgarian farmers were busy harvesting rose petals for their renowned oil this week, about a month earlier than the historical norm due to climate change that has ushered in warmer and more humid springs.

Agencies via Xinhua