Countries by Average Annual Rainfall

Countries ranked by average annual rainfall, in millimetres. Colombia records the highest average at 3,240 mm, ahead of Papua New Guinea on 3,142 mm and the Solomon Islands on 3,028 mm. Egypt closes the table on 51 mm.

The range here is the widest of almost any national comparison on the site: Colombia receives 64 times as much rain as Egypt. Put differently, an average day in Colombia delivers what Egypt receives in more than two months. The top five countries all lie on or near the equator — Colombia, Papua New Guinea, the Solomon Islands, Malaysia (2,875 mm) and Indonesia (2,702 mm) — while the bottom two, Egypt and Libya (56 mm), sit in the Sahara.

Norway's 1,414 mm is the interesting middle case. It is nowhere near the tropics, and it still receives more rain than most of Europe because moist Atlantic air is forced upward against its western mountains. Rainfall is driven by where air masses meet terrain, not by latitude alone.

A national average is a blunt instrument for a country of any size. Colombia's figure combines Pacific coastal regions that are among the wettest inhabited places on earth with drier highlands and plains; averaging them produces a number that describes nowhere in particular. The same is true in reverse for large arid countries, where a single wet region is diluted across a desert.

These are long-term climatological averages rather than a measurement for one year, so they are stable over time and do not reflect any particular season's weather.