Weather Trends for Portland, Yamhill Valley and Willamette Valley

Seasonal Expectations:

What's it going to be like in Portland and the Willamette Valley?

Planning a trip to Oregon? Here's some information to help you anticipate the kinds of weather conditions you may experience.

First, let's clear up the "rainy Oregon" perception. Yes, it rains a lot in Oregon ... if you're visiting during the months of November, December, January, February or March.

If you plan your trip in July, August or September, you can expect wonderful and dry days. It's impossible, of course, to predict what the weather will be like a few months from now. Looking back at past weather data, however, helps create some clear pictures.

The following charts show the average daily high and low temperatures each month for selected locations throughout the state. The charts also list the average monthly rainfall (and snowfall where appropriate). These averages where established by the Oregon Climate Service for the years 1971-2000.

Portland / Willamette Valley Temperature and Precipitation Averages
- 1971-2008
Oregon Climate Service

Temperatures are daily averages; precipitation and snowfall are monthly average inches

  Jan Feb Mar April May June July Aug Sept Oct Nov De
Eugene
 
                       
High Temp 46.5 50.7 55.9 60.6 66.8 73.3 81.5 81.9 76.6 64.6 52.1 45.7
Low Temp 33.0 34.9 36.7 38.9 42.7 47.0 50.8 50.8 46.7 40.5 37.2 33.3
Precip 7.65 6.35 5.80 3.66 2.66 1.53 .64 .99 1.54 3.35 8.44 8.29
Portland                        

High Temp

45.5 50.1 55.5 60.8 67.0 72.6 78.9 79.1 74.2 63.0 51.4 45.5
Low Temp 36.7 38.5 40.7 43.5 48.5 53.2 57.3 57.9 54.6 48.1 41.8 37.3
Precip 6.24 5.07 4.51 3.10 2.49 1.60 .76 .99 1.87 3.39 6.39 6.75
Salem                        
High Temp 47.0 51.2 56.3 61.1 67.5 74.0 81.5 81.9 76.6 64.5 52.4 46.4
Low Temp 33.5 34.7 36.6 38.8 43.6 48.4 52.0 52.1 47.7 41.3 37.9 33.9
Precip 5.84 5.09 4.17 2.76 2.13 1.45 .57 .68 1.43 3.03 6.39 6.46