Macau is situated 60 kilometres (37 mi) southwest of Hong Kong and 145 kilometres (90 mi) from Guangzhou of Mainland China. It also has 41 kilometres (25 mi) of coastline, yet only 310 metres (1,000 ft) of land border with Guangdong of Mainland China. It consists of the Macau Peninsula itself and the islands of Taipa and Coloane, which are now connected by landfill forming Cotai. The peninsula is formed by the Zhu Jiang (Pearl River) estuary on the east and the Xi Jiang (West River) on the west. It borders the Zhuhai Special Economic Zone in mainland China. The main border crossing between Macau and China is known as the Portas do Cerco (Barrier Gate) on the Macau side, and the Gongbei Port of Entry on the Zhuhai side.
Macau Peninsula was originally an island, but a connecting sandbar gradually turned into a narrow isthmus, thus changing Macau into a peninsula. Land reclamation in the 17th century transformed Macau into a peninsula with generally flat terrain, though numerous steep hills still mark the original land mass. Alto de Coloane is the highest point in Macau, with an altitude of 170.6 metres (559.7 ft). With a dense urban environment, Macau has no arable land, pastures, forest, or woodland.
Macau has a humid subtropical climate (Köppen Cwa), with average relative humidity between 75% and 90%. Similar to much of South China, seasonal climate is greatly influenced by the monsoons, and differences in temperature and humidity between summer and winter are noticeable, though not as great as in mainland China. The average annual temperature of Macau is 22.7 °C (72.9 °F). July is the warmest month, the average temperature being 28.9 °C (84.0 °F). The coolest month is January, with a mean temperature of 14.5 °C (58.1 °F).
Located on China's southern coast, Macau has ample rainfall, with average annual precipitation being 2,120 millimetres (83 in). However, winter is mostly dry due to the influence of the vast Siberian High affecting much of East Asia. Autumn in Macau, from October to November, is sunny and still pleasantly warm with lower humidity. Winter (December to early March) is generally mild with temperatures above 13 °C (55 °F) most of the time, although it can drop below 8 °C (46 °F) at times. Humidity starts to increase from late March. Summer is very warm to hot (often rising above 30 °C (86 °F) during the day). The hot weather is often followed by heavy rain, thunderstorms and occasional typhoons.
Source : https://en.wikipedia.org/wiki/Macau