U Hla Tu, director of the department, said a longer pre-monsoon period means higher temperatures, thunderstorms, strong winds and heavy rains.
The department said that daytime temperatures for May will be higher by 1.5 degrees Celsius in southern Sagaing, Mandalay, Magwe, Bago and Yangon regions, and will be normal in northern Sagaing, Ayeyarwady, Tanintharyi, Kachin, Shan, Chin, Rakhine, Kayah, Kayin and Mon states and regions.
There is an 80 percent chance of El Nino forming from May to June, but that is likely to drop to 62pc in September, according to a statement released by the International Observatory for Pacific Ocean Sea Surface Temperatures.
Although this is not an El Nino year, the country has experienced extremely dry weather during the summer. Temperatures reached record highs this year, including in Yangon in April.
In moderate to strong El Nino years, Myanmar normally experiences dry and extreme weather. In 2016, which was a strong El Nino year, Chauk, Sagaing, Taungdwingyi, Yamethin, Meiktila, Kyaukse, Heho, and Mogok had record highs.