Located in the southern side of the Tropic of Cancer, Chang'an has a sub-tropical Atlantic Climate with

greenery and pleasant weather all year round, it is also known as the Land of Fish and Grain for its abundant economical products of bananas, litchis, tangerines, and local specialties such as clamworms, rice birds, crabs, lenoks and gray mullets.

    Dalingshan Mountains mainly made up of granites, are located in the north of Chang'an Town. The masiff, with a fairly thick mantle rock above five meters, is a loess and red clay land. Lianhuashan Mountain, 513.4 meters above the sea level, towers above all mountains that stretch for 18 kilometers in the north of Chang'an Town from Baishishan Mountain at Congtou County in the east to Tongushan Mountain at Shanjiao County in the west. There are green low hills lying close to the mountains in the north. 

    The south of Chang'an is mainly a stretch of plain and mud flat. The flat, most part of which is rich land, is crisscrossed by rivers and river branches, and there is also a vast mud flat, which is 0.1 to 0.6 meters above sea level to the south of the sea embankment of Chang'an. The mud flat is divided into two parts, the one near from the coast is 0.4 to 0.6 meters above the sea level, and the one used for mudflat aquaculture far from the coast is 0.1 to 0.3 meters above the sea level. 

    Species of the earth of Chang'an is divided into mountain land (low hill land and downland included), dry land and rice soil. The mountain land, made up of yellow earth and red earth, is mainly distributed in the north; the dry land, made up of Layeritic red earth, sand and mud, is mainly distributed in the middle, while rice soil, made up of salty earth, neutral earth and pit earth, is mainly distributed in the south, middle and north.

Climate
    Chang'an is located in the sub-tropic at low latitude of the Northern Hemisphere, east of the estuary of the Pearl River Delta and beside the sea. The climate here is Sub-tropic Atlantic Climate, it is warm and humid with abundant sunshine and rainfall. Compared with inland areas at the same latitude, Chang'an is warmer in winter and cooler in summer. This place so rich in resources of water and heat, has a superior advantage for crops and tropical economical products. 

Rainfall
    Chang'an is rich in rainfall with an annual rainfall of 1,750 mm, and the monthly rainfall averages from 100 to 200 mm during the rainy seasons from April to September. The evenly divided rainy season and megathermal period is very good for the high-speed growth of crops of various kinds from July to December.

Temperature
    Chang'an has an enjoyable climate, with an annually average temperature of 22 oC, which is very suitable for not only the growth of agricultural products of rice and sweet potatoes, but also tropic crops such as bananas, litchis, longans, papayas and mangoes. 

Sunshine
    Chang'an has a very good condition of sunshine, with an annual ratio of sunshine of 43%, and actual duration of daytime above 1,800 hours. There is an insignificant difference of daytime between winter and summer. Abundant sunshine is very good for the photosynthesis of various crops.

Wind
    With an annual wind speed of 2.1 meters per minute, Chang'an is not a place with a high wind speed; the wind direction has a significant seasonal variation, with mainly northerly divergent wind in winter and southerly divergent wind. Summer is longer while winter is shorter in Chang'an, and as it is beside South Sea, the weather could be adjusted by the sea wind, thus Chang'an is not too hot in summer, or too cold in winter. However, it may suffers typhoon during the period from May to August.

Cold-air Outbreak
    Chang'an, during the period after Cold Dew (17th solar term) of a year and before the Waking of Insects (3rd solar term) of the next year, always suffers cold air from the north, which may ruin thermophilous crops such as bananas and papayas. In early spring, the cold air, though has got worse, may visit southern China to cause low temperature weather with rain. It may make the early sown rice shoots rotten.

Tide
    The 1st and 15th every month of the lunar calendar in Chang'an is the great tide period, which is also known as the Rise of Water. Every eighth day and the 23rd day of the lunar calendar month is called Minor Nighttime Water-Rise. In spring and fall, the tide is regular at night and daytime. Local residents has made full use of the tides and arrange their farming and fishing according to the schedule of the tides in different seasons. 

Local Specialties
    Dongguan is rich in specialties. The 50-miles of coastline with shallow seawater is ideal for raising oysters, which are known for the big size and good quality. Rivers, big and small, are crisscrossing in Chang'an. Adjacent to the confluence of Pearl River and the sea, Chang'an has exported large quantity of high quality fish & shrimp every year overseas because of the rich food resources for fishes and mild-temperature seawater nearby. 

    Chang'an has some rare animals like hedgehogs, otters, Hehua Bird (a kind of sparrow), wild ducks.

    The major economic crops include waterweeds, sugar cane, banana, mandarin orange, citrus, jute, peanuts, lychee and vegetables. Waterweed products are traditional exports of Chang'an. There are also other known local specialties in Chang'an like He-Cong (a little worm full of nutrition), Dajing-onion, crab, Wutou fish, Huayu fish, etc.