Floods and the threat of flooding continue until the end of the June-to-September rainy season. See link below.
huricane season
in the spring
There is no answer.
The flood affected the harvest season because if the flood took too long to dry then then there would be a delay in the seasons.
summer?
during flood season in flood zones
march
from $1500-$2300. it depends what season your flight will be.
The last flood was in may 2011
Between July and November
September through till March
USAID may have something for you www.usaid.gov/stories/ethiopia/fp_ethiopia_scholarship.html