Ca Mau is a coastal delta province, located in the interior region of the northern hemisphere, near the equator, and also located in the Asian monsoon region, so the mild climate of Ca Mau is in the equatorial, tropical monsoon, with 2 distinct rainy and sunny seasons.
The rainy season lasts from May to November, on average from 170 to 200 days/year. In the west and southwestern areas of the province, the rainy season usually starts earlier and ends later than other areas. Average rainfall between months in the rainy season is not much different and ranges from 200mm to 400mm/month.
The sunny season is from November to April next year. The annual average temperature ranges from 26,6 degrees C to 27,7 degrees C; the highest average temperature of the year is in April and May, about 28,6 degrees C. Particularly from 2001 to 2005, the average temperature in April ranged from 29,2 degrees C to 29,7 degrees C. The lowest average temperature in January is about 25,6 degrees C. Thus, the average temperature difference between the hottest month and the coldest month is about 3,0 degrees C.
The average annual sunshine time is 2,269 hours. The average annual evaporation is about 1,000 mm; In the dry season (March – April), evaporation is nearly 130 mm/month. The annual average humidity is 83%, the dry season is low, especially in March, the humidity is usually about 50%.
The wind regime is both influenced by tropical characteristics and influenced by the monsoon mechanisms in Southeast Asia. Every year, there are 2 main wind seasons: winter monsoon (northeast monsoon) from November of previous year to April of next year and summer monsoon (southwest monsoon), starting from May to October. In the dry season, the prevailing wind direction is northeast and east. In the rainy season, the wind prevails in the southwest or the west. The average annual wind speed in Ca Mau is small, inland is only from 1.0 to 2.0m/sec, the stronger offshore wind is only 2.5 to 3.5m/sec. In the rainy season, there are occasional thunderstorms or tornadoes up to level 7 and 8. Storms are but not many and not great. The weather and climate in Ca Mau are favorable for the development of fishery – agriculture – forestry towards large commodity production.