I have previously defended Portland’s weather. The point I made was that, while it absolutely rains more often (more days per year) in Portland than most other large cities, we get less rain overall (in terms of depth of water). These maps visualize the latter point using average precipitation from 30-yr normals (1981-2010). Note that almost half of Portland’s precipitation occurs in November-January, but the combined precipitation in July and August is less than 4% of the annual total. To emphasize this seasonality, I’ve also mapped normals for July and December, when Portland is drier and wetter, respectively, than most of the country.

Data source: http://www.prism.oregonstate.edu/normals/