The best times to visit Willamette Valley for ideal weather are
May 14th to September 30th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Willamette Valley Travel Guide
Other Willamette Valley Travel Info
Weather in Willamette Valley
Average temperatures in Willamette Valley vary greatly. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a fair chance of precipitation about half of the year. The area is less temperate than some — in the 32nd percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Willamette Valley, the hottest months are July, August, and then September. See average monthly temperatures below. The warmest time of year is generally mid August where highs are regularly around 88.5°F (31.4°C) with temperatures rarely dropping below 55.5°F (13.1°C) at night.
Willamette Valley Temperatures (Fahrenheit)
Willamette Valley Temperatures (Celsius)
The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.
Willamette Valley Perceived Temperature (F)
Willamette Valley Perceived Temperature (C)
Average Willamette Valley Temperatures by Month
Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Willamette Valley are August, July, and then June. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early July. For example, on the week of July 2nd there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in mid December with an average of 3 days of significant precipitation the week of December 17th.
When can you find snow in Willamette Valley? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Willamette Valley.
Snow on the Ground
The graph below shows the average snow on the ground in Willamette Valley (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
Humidity and Wind
Willamette Valley has some extremely humid months, with other moderately humid months on the other side of the year. The least humid month is July (47.7% relative humidity), and the most humid month is December (81.6%).
Wind in Willamette Valley is usually calm. The windiest month is July, followed by August and June. July’s average wind speed of around 7.5 knots (8.7 MPH or 14 KPH) is considered “a gentle breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early August where average top sustained speeds reach 15.7 knots, which is considered a moderate breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Willamette Valley.
The graph below shows wind speed (max and average) in knots.
Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
|Month||Avg. Wind||Avg. Wind Feel||Sustained High Wind||High Wind Feel|
|Jan||3.9||Barely noticeable||10.6||Gentle breeze|
|Feb||4.6||Light breeze||11.7||Significant breeze|
|Mar||5.6||Light breeze||13.4||Gentle breeze|
|Apr||5.4||Light breeze||13.3||Significant breeze|
|May||5.6||Light breeze||13.4||Gentle breeze|
|Jun||5.9||Light breeze||13.4||Significant breeze|
|Jul||7.5||Gentle breeze||15.1||Gentle breeze|
|Aug||6.7||Light breeze||15||Significant breeze|
|Sep||5.6||Light breeze||13.7||Gentle breeze|
|Oct||4.5||Light breeze||11.6||Significant breeze|
|Nov||4.6||Light breeze||11.6||Gentle breeze|
|Dec||4.8||Light breeze||12||Significant breeze|
Show Relative Humidity by Month
|Month||Avg. Relative Humidity|
Is it Safe to Travel to Willamette Valley?
Our best data indicates this area is generally safe. As of Oct 07, 2019 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Sep 23, 2019.
The Busiest and Least Crowded Months
The busiest month for tourism in Willamette Valley, OR, US is August, followed by July and June. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Willamette Valley in December. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
Overall Willamette Valley Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderately cold. Highs range from 75.7°F (24.3°C) and 54.7°F (12.6°C) with warmer temperatures in the later months. Rain is somewhat common with 4 to 9 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.
Summer (June through August)
The middle-year months have very comfortable weather with high temperatures that are comfortable. These months see the least precipitation with 1 to 2 days of precipitation per month. June – August is the busiest season for tourism in Willamette Valley, so lodging and other accommodations may cost more than usual.
Fall (September through November)
Fall daily highs range from 84.8°F (29.3°C) and 50.2°F (10.1°C), which will feel chilly given the humidity and wind. It rains or snows a significant amount: 2 to 7 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.
Winter (December through February)
Weather is too cold this time of year in Willamette Valley to be enjoyable for warm weather travelers. The average high during this season is between 55.3°F (12.9°C) and 46.3°F (7.9°C). On average, it rains or snows a fair amount: 7 to 9 times per month. These times of year are fairly slow with tourists.