The best times to visit Castle Rock for ideal weather are

May 21st 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.



Other Castle Rock Travel Info

Weather in Castle Rock


Average temperatures in Castle Rock 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 33rd 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 Castle Rock, the hottest months are August, July, and then September. See average monthly temperatures below. The warmest time of year is generally mid August where highs are regularly around 82.7°F (28.2°C) with temperatures rarely dropping below 56.6°F (13.7°C) at night.

Castle Rock Temperatures (Fahrenheit)


Castle Rock Temperatures (Celsius)


“Feels-Like” Temperatures

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.

Castle Rock Perceived Temperature (F)


Castle Rock Perceived Temperature (C)



Average Castle Rock 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.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 46.7 39.7 35.2
Feb 51.3 42.4 36.4
Mar 56.1 45.9 39.3
Apr 60.7 48.9 41
May 67.9 55.1 46.5
Jun 72.3 59.8 51.4
Jul 79.8 65.1 55.5
Aug 80 65.4 55.8
Sep 75.3 61.2 51.7
Oct 63.5 53 46.1
Nov 52.2 45 40.1
Dec 45.4 39.7 35.6

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 8.2 4.3 1.8
Feb 10.7 5.8 2.4
Mar 13.4 7.7 4.1
Apr 15.9 9.4 5
May 19.9 12.8 8.1
Jun 22.4 15.4 10.8
Jul 26.6 18.4 13.1
Aug 26.7 18.6 13.2
Sep 24.1 16.2 10.9
Oct 17.5 11.7 7.8
Nov 11.2 7.2 4.5
Dec 7.4 4.3 2



Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Castle Rock are July, August, and then September. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early August. For example, on the week of July 30th there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in late March with an average of 3 days of significant precipitation the week of March 26th.

When can you find snow in Castle Rock? 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 Castle Rock.

Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Castle Rock (in).

Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 29% 0 4.8
Feb 31% 0 3.3
Mar 38% 0 4.8
Apr 31% 0 2.8
May 25% 0 2.8
Jun 15% 0 1.5
Jul 3% 0 0.4
Aug 4% 0 0.5
Sep 14% 0 2
Oct 23% 0 3.1
Nov 33% 0 4.5
Dec 37% 0 5.7

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 29 0 12.2
Feb 31 0 8.4
Mar 38 0 12.2
Apr 31 0 7.1
May 25 0 7.1
Jun 15 0 3.8
Jul 3 0 1
Aug 4 0 1.3
Sep 14 0 5.1
Oct 23 0 7.9
Nov 33 0 11.4
Dec 37 0 14.5


Humidity and Wind

Castle Rock has some very humid months, with other comfortably humid months. The least humid month is July (58% relative humidity), and the most humid month is January (78.2%).

Wind in Castle Rock is usually calm. The windiest month is December, followed by November and January. December’s average wind speed of around 4.9 knots (5.7 MPH or 9.1 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in mid November where average top sustained speeds reach 12.8 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Castle Rock.

Avg. Relative Humidity


The graph below shows wind speed (max and average) in knots.

Max Sustained Wind
Average Daily Wind

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 4.6 Light breeze 11 Significant breeze
Feb 4.1 Light breeze 10.8 Gentle breeze
Mar 4.5 Light breeze 11.9 Significant breeze
Apr 3.9 Barely noticeable 11.3 Significant breeze
May 3.8 Barely noticeable 10.8 Significant breeze
Jun 3.7 Barely noticeable 10.3 Gentle breeze
Jul 4.2 Light breeze 10.4 Significant breeze
Aug 3.6 Barely noticeable 9.9 Gentle breeze
Sep 3.4 Barely noticeable 9.9 Significant breeze
Oct 3.7 Barely noticeable 10.2 Gentle breeze
Nov 4.7 Light breeze 11.3 Significant breeze
Dec 4.9 Light breeze 11.3 Significant breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 78.2%
Feb 73.4%
Mar 68.6%
Apr 62.6%
May 60.1%
Jun 60.8%
Jul 58%
Aug 59.4%
Sep 63.1%
Oct 71.8%
Nov 76.1%
Dec 77.7%


Is it Safe to Travel to Castle Rock?

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 Castle Rock, WA, 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 Castle Rock 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

Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is somewhat extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 55.1 in December means 55.1% of the tourists vs. August.



Overall Castle Rock Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderately cold. Highs range from 71.3°F (21.8°C) and 52.3°F (11.3°C) with warmer temperatures in the later months. Rain is somewhat common with 8 to 12 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 comfortably cool weather with high temperatures that are comfortable. These months see the least precipitation with 1 to 4 days of precipitation per month. June – August is the busiest season for tourism in Castle Rock, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 79.3°F (26.3°C) and 48.8°F (9.3°C), which will feel chilly given the humidity and wind. It rains or snows a significant amount: 4 to 10 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 Castle Rock to be enjoyable for warm weather travelers. The average high during this season is between 52.9°F (11.6°C) and 44.1°F (6.7°C). On average, it rains or snows a fair amount: 9 to 11 times per month. These times of year are fairly slow with tourists.


Best Times to Travelthe United States › Castle Rock, WA, US