Myanmar receives its annual rains primarily from the South-West monsoon from mid-May to mid-October. The precipitation, however, varies depending on the locality, elevation and months. July is generally regarded as the period of maximum rainfall throughout the country.

The heaviest annual rainfall varying from 100 to 200 inches are recorded in Rakhine State, part of Kachin State, Kayin State and the Tanintharyi coastal regions, including part of Mon State. While the annual rainfall is below 40 inches in the Dry Zone, precipitations in other parts of Myanmar vary from 40 to 80 inches during the monsoon.

The Dry Zone, where over 40% of all croplands are located, is prone to moisture deficiency even during the monsoon season. But major irrigation works in Magway Divisions have, to some extent, mitigated the handicaps in the region. The areas locative to the different ranges of rainfall are shown in the Map-1.

The South-west monsoon is the main source for Myanmar's seasonal rains, but Easterly Winds and local depressions across the Gulf of Thailand often bring post monsoon rains, that sometimes lead to delays in the harvesting operation of rice and in some abnormal years even cause considerable crop losses in the field.

The agroclimatic conditions of Myanmar range from that of equatorial to cool-temperate, and remain suited to a large variety of crops such as equatorial plantation crops (rubber, cocoa, oil palm and coconut) and temperate fruits (apples and pears), besides the common food and industrial crops of Monsoon Asia. The annual rainfall by State and Division is described below:-             See Table