Mexican coffee traders and exporters are investigating the potential damage to the current 2009-10 harvest after farms in several central regions have been hit by a week of severe cold weather, traders and exporters said Tuesday.

Mexico is currently hit by a severe cold front that has seen temperatures dipping to just a few degrees above zero in the last week, causing speculation in the New York arabica futures market as to the exposure of frost damage.

"We have talked to a number of exporters in Mexico and they have told us that effectively there has been frost in several regions of Puebla and Veracruz, but we don't know yet if there has been any damage," said one trader.

"There was definitively frost in the regions of northern Puebla and neighboring Veracruz, but it's still too early to tell whether there actually has been any damage to the crop," another trader with an exporter told Dow Jones Newswires.

The Mexican coffee growing areas which traditionally have been exposed to frost damage include the very northern most part of the central state of Puebla around Xicotepec de Juarez, and the same region in neighboring Veracruz state.

Veracruz is Mexico's second largest producing state while Puebla is the country's third largest coffee growing state, but the regions exposed to frost damage have traditionally only accounted for up to 150,000 60-kilograms of production.

Both exporters and traders said they expect to get a more clear view of the potential damage in the next few days, but the cold front is expected to continue with temperatures forecast to dip lower again from Thursday.

Frost damage to coffee can occur after extended periods for at least 10 hours of continuing cold weather with temperatures below 3 degrees Celsius, which can cause the coffee cherries to "burn" before wilting and falling of the tree.

Even if coffee trees are hit with frost, it doesn't necessarily result in the crop being damaged unless the time in which the branches and cherries are exposed to frost is prolonged. Mexican producers recently started harvesting of the 2009-10 cr and ripe cherries are therefore more vulnerable to the effects of adverse weather.