"Consecutive seasons of poor rainfall, a possible failure of the current Heys/Dada rains, high staple food prices and a significant reduction in emergency food aid distribution are pushing households towards extreme food insecurity," the Famine Early Warning System Network (FEWS Net) said.
The Heys/Dada rains last from October to February and are the main source of water, especially in the coastal grazing belt.
"In most areas, no significant rains were observed in November, normally the period of peak rainfall, suggesting that the season may be a complete failure," FEWS Net said in an 11 January alert. "Earlier rains in 2009 were also below normal."
The situation comes at a time when the UN World Food Programme (WFP) has reduced general emergency food aid distributions in most pastoral areas by nearly 74 percent, compared with last year.
The reduction followed a May 2009 assessment that had shown a significant improvement in water and pasture conditions, especially in the coastal belt. Food and energy prices were also stabilizing.
"WFP is following the current situation in Djibouti closely together with the government and other partners and is concerned by the poor performance of the rains in some parts of the country," Marcus Prior, WFP spokesman in Nairobi, said.
"Up to October 2009, WFP was providing general food rations to 80,000 vulnerable people in Djibouti," Prior told IRIN on 13 January. Following the assessment, that number was reduced to 25,000.
The poor rains have already led to livestock deaths, FEWS Net said, particularly in the northwest and southeast pastoral zones. Some households are failing to meet basic food and water needs.
"The rural population in need of emergency assistance, both food and non-food, is expected to increase in the coming months to 80,000 to 100,000 persons," it noted. "Current emergency food aid distribution is inadequate and should expand to meet the expected caseload."
In central pastoral zones, people had already started selling their remaining livestock, taking children out of school, reducing dietary intake, and migrating to cities in search of casual labour.
Prior said WFP, with regional authorities, was planning to roll out food-for-work activities for the moderately food insecure. These would include building or rehabilitating access roads, and agricultural and water supply infrastructure.
"It is expected that up to 21,500 additional people will benefit from these projects," he added. "WFP's nutrition programme in Djibouti, targeting over 3,200 of the most vulnerable mothers and their children, continues."
Two-thirds of Djibouti's estimated 800,000 people live below the poverty line, 10 percent in extreme poverty, according to Djibouti health ministry statistics. At least 85 percent of the population lives in urban areas, but 60 percent are unemployed.
Djibouti, according to the International Federation of Red Cross and Red Crescent Societies, is also fundamentally dependant on imported cereals. Food prices are approximately 30 percent above the market average.
According to the UN Children's Fund, UNICEF, an estimated 30,000 children were acutely malnourished last year. In an update for December 2009-February 2010, UNICEF said global acute malnutrition (GAM) prevalence among children under five was at a critical level of 28.8 percent nationally.