Climate and waters. – Bimnania enters the climatic zone of the monsoons, but the relief determines profound local modifications. There are really three seasons: a cool and dry one from the end of October to the whole of February, a warm one that is also without rain, from March to the end of May or the beginning of June, and the rainy season, from June to October. The hottest month is generally April or May, the coolest is January. Along the coast, and especially in the south (Tenasserim), the diurnal and annual temperature ranges are small (4 °, 4 in Moulmein, 5 °, 6 in Rangoon); they increase, while in the dry zone (11 °, 2 in Mandalay). At the same time, the average annual temperature decreases, which in the south is about 26 ° -27 °, while in the north, again at sea level, the temperature fluctuates between 17 ° (January) and 29 °, 4 (May).
From October to May, Burma is under the influence of the NE monsoon, which the arrangement of the relief blows almost directly to the south: it is a fresh wind that decreases in intensity towards the end of the cool season. The transition to the SW monsoon. thunderstorms are announced as early as the end of May, but the rains do not generally arrive before June 15: the coasts receive most of them, so much so that the Arakan has over 5 m. In Rangoon the figure drops to 2537 mm. The central portion of the country is almost excluded from the benefit and receives only 500 mm. of annual rainfall (Mandalay: 855). On the plateau, as it is easy to understand, the annual temperature is much milder and the rainfall increases again.
The waterways of Burma can be arranged in different categories: the short, rapid and numerous ones that flow down from the Arakan Yoma in the Bay of Bengal; the two central rivers, Irawady (v.) and Sittang, with their tributaries; the Saluen system (v.) which collects the waters of the Shan plateau; finally, the various short rivers that run from the hills of Tenasserim to the Gulf of Martaban. The largest lake is the shallow Inle and remnant of a larger ancient one, in a depression in the Shan country; also noteworthy is the Indawgyi in Upper Burma, near Mogaung. In all the lowlands there are numerous small lakes derived from abandoned river meanders.
Vegetation and fauna. – The remarkable climatic variations correspond to analogous varieties in the vegetal mantle. Above 1000 m., That is, where occasional frosts occur, evergreen oak or pine woods vegetate or large areas of open land with ferns and grasses meet. Higher up are spots of rhododendrons. Below the indicated line, spontaneous vegetation is related to rainfall: 1. with over 2000 mm. rain settles the evergreen tropical forest; the tree species are numerous, but more than half belong to the Dipterocarpacee; the wood is hard and little used; 2. where they fall from 1000 to 2000 mm. the wood typical of monsoon countries develops, which loses its leaves during the dry season: among the many useful tree essences is the precious teak and pyinkado (Xylia dolabriformis); 3. under 1000 mm. the wood becomes impoverished and passes to scrubs and shrubs; true grasslands are practically absent; 4. Large areas of the Irawady delta are covered by the coastal tropical forest, in which many trees reach a height of over 30 m. and are of considerable value.
The harmful agricultural methods of indigenous farmers have, in the past, destroyed a large part of the woodland. It was customary to cut down and set fire to a stretch of forest, cultivate the field (taung – ya) thus obtained for two or three years, as long as the freshness of the soil lasted, and then abandon it for another place. I taung – ya abandoned, they are rarely reoccupied by the woods, and mostly they present themselves with a tangle of bamboo, ferns and grasses. For over half a century, however, the Forestry Department has been working to protect forests and the most valuable are now state reserves. The timber – mainly teak for construction and pyinkado for railway sleepers – is processed by the government and licensed companies under careful control: it ranks third among Burmese exports and in recent years has reached about 150,000 tons. for a value of one and a half million pounds, that is 142 million Italian lire.
The fauna is rich and varied. Anthropoids are represented by two gibbons and a dozen species of apes are known. The tiger is common throughout the province and so is the leopard and various species of wild cats. The Himalayan and Malayan black bears are found in the mountains. Elephants still abound where the vegetation is thickest and every year they are captured to train them for forestry work; the two species of rhinos are now rarer. Wild buffalo (saing) and various species of deer and fallow deer (gyi, thamin, sambar) are very common. Big game hunting requires a permit and many of the larger animals enjoy the benefit of a hunting ban period.
The parriah, a half-wild dog, populates every village and bats can be seen everywhere, including the huge “flying fox”, which during the day sleep hanging, thousands, from the branches of trees even in the most populous streets of Rangoon. Among the many birds are the small brightly colored parrots, the paddy-bird and countless crows; among the reptiles the gecko (tankté) and many snakes, including the python.
Natural regions. – Burma can be divided into seven natural regions: 1. Arakan; 2. the western chains; 3. the northern mountain region with the sources of the Irawady and Chindwin; 4. the arid district; 5. the deltas; 6. the Shan plateau; 7. the Tenasserim. The first two and the last two are subdivisions of the elevated morphological zones; the others, parts of the great central basin (see arakan, shan, pegu, tenasserim). In the middle of the latter, in the dry district, is the heart of Burma and the seat of the old capitals: Pagan, Shwebo, Ava, Amarapura and Mandalay, with Prome on its southern edge. But it is natural that the British capital of the province is Rangoon, by the sea.