Vietnam's coffee exports in April were equivalent to half of Brazil's total exports, confirming the wide gap between the world's two largest coffee exporters.
The International Coffee Organisation's (ICO) report, released at the end of May, said Vietnam shipped only 1.45 million bags of coffee in April, posting a 42.8 percent year-on-year decrease, the largest drop among the top coffee exporting countries.
Despite being the world's second largest coffee exporter, the country's export was much less than Brazil's total of three million bags.
Colombia and Honduras, which are in third and fourth position respectively, saw their exports increase by 16 to 20 percent in the period.
The Vietnam Coffee and Cocoa Association said the decrease in coffee output was due to prolonged bad weather.
The association said the Central Highlands faced a severe water shortage.
In the last 10 years, the region has suffered from the most severe drought on record, pulling down coffee output and exports to the lowest level in the past five years.
The website also forecast there would be 134 days of hot weather in the region by 2050, and 230 days by 2100, thus affecting coffee cultivation.
Vietnamese coffee exports have also faced a fall in value due to decreasing prices.
Statistics from the General Department of Customs said coffee export turnover in April was US$ 225 million, bringing the total to US$ 968 million in the first four months of the year. This represented a 39 percent fall over the same period last year.