At the extreme northeastern corner, DPRK shares a short border of about 18 km with Russia. Lack of precipitation combined with poor soil fertility makes land at elevations higher than 400 m unsuited for agriculture other than grazing. The climate is generally temperate oceanic, but changes to continental in the northwest where the country connects with the Asian landmass. Summers are warm and humid and of relatively short duration. Winters tend to be cold and dry, and in the northernmost provinces last for up to 5 months.
Rainfall is geographically and seasonally irregular.
In most of the country, up to half of the annual rainfall occurs during the three summer months. DPRK lies in AEZ 6, characterized as warm subhumid subtropical with summer rainfall. The population is concentrated in the coastal plains and in the river valleys, where agriculture can be practiced. Importance of rice Rice has been cultivated in the DPRK for about 3000 years. It is the main and staple crop.