The president also directed cabinet ministers and government officials to lead prayers at the nearest congregation near them, a statement signed the Chief Secretary to the Government Lloyd.A. Muhara said.
In January this year, Mutharika made a similar order after a dry spell and worsening pest infestation threatened the country's staple maize crop.
Malawi is periodically hit by food shortages as the tropical southern African country relies heavily on rain-fed agriculture and most of its maize is grown on small plots by subsistence farmers.
The current dry spell has been exacerbated by an outbreak of crop-munching fall armyworms, a pest from Latin America that first threatened African crops late in 2016.