Warm weather and a strong export market in the first six months of the year have helped German brewers reverse a long decline in beer production.

The total volume of beer produced in Germany in the first half rose on an annual basis for the first time in four years, up 1.0 percent to 4.946 billion liters, government data showed Thursday.

“It’s definitely down to the temperature,” said Juergen Hammer, an official at the Federal Statistics Agency, pointing to an unusually warm April and May that had boosted demand.

The amount of beer produced for domestic consumption in the first six months rose from the first time since the hot summer when Germany hosted the soccer World Cup in 2006, edging up by 0.2 percent.

Although the average German of legal drinking age still puts away about 120 liters of beer a year — roughly a glass a day — consumption has fallen in recent years as Germans turn to wine and other beverages.

However, foreigners are developing an increasing taste for German beer — the ingredients of which have been subject to strict government regulation since the 16th century.

The volume of beer produced for export, just over a tenth of national production, grew by an annual 5.3 percent in the first six months of 2011, with a marked 13.6 percent rise in beer destined for outside the European Union.

Most German brewers are relatively small, privately owned companies, although one of the best known international brands produced in Germany, Beck’s, is owned by the world’s largest brewer, Belgium’s Anheuser-Busch InBev.