MEXICO CITY, June 1 (Xinhua) -- An intense and prolonged heatwave has broken temperature records for May in five Mexican states, although no casualties have been officially reported to date, the government announced on Friday.

The general coordinator of the national weather service, SMN, Alberto Hernandez, told a press conference that May 2018 saw an average temperature of 32.3 degrees centigrade nationwide, the fifteenth hottest on record.

However, the states of Hidalgo, Chihuahua, Sinaloa, Zacatecas and Jalisco broke historical highs going back more than 50 years.

Hernandez said that certain communities in Hidalgo and Sinaloa saw temperature reach 49 degrees centigrade, beating record highs registered in 1964 and 1968 respectively.

"There is an intense and prolonged heatwave in most of the territory," he said, adding that it was caused by a high-pressure front along the western coast of Mexico, which is causing more hours of sunlight.

Weather predictions state this heatwave is likely to last until June 5, when the system will move to the north and rain clouds will form over central Mexico.

The Ministry of the Interior has also announced that a state of emergency has been declared in 573 municipalities across 22 states with food and water being delivered to avoid dehydration.