San Juan County, WA Climate

San Juan County has a mild, temperate climate. The average temperature range is between the low 50s and mid-70s with very little precipitation throughout the year. Summers are typically dry and sunny, while winters tend to be more damp and cool. Snowfall is infrequent, but when it does occur it generally falls in short bursts during the coldest months of December through February. The area is also known for its pleasant ocean breezes that help to keep temperatures comfortable all year round.

San Juan County, Washington gets 28 inches of rain, on average, per year. The US average is 38 inches of rain per year.

San Juan County averages 6 inches of snow per year. The US average is 28 inches of snow per year.

On average, there are 158 sunny days per year in San Juan County. The US average is 205 sunny days.

San Juan County gets some kind of precipitation, on average, 138 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.

Weather Highlights

Summer High: the July high is around 71 degrees
Winter Low: the January low is 36
Rain: averages 28 inches of rain a year
Snow: averages 6 inches of snow a year

Bestplaces Comfort Index

The annual BestPlaces Comfort Index for San Juan County is 7.2 (10=best), which means it is more comfortable than most places in Washington.

9 Summer - 5.6 Winter

August, July and September are the most pleasant months in San Juan County, while December and January are the least comfortable months.

Climate	San Juan, Washington	United States
	27.7 in.	38.1 in.
	5.5 in.	27.8 in.
	137.9 days	106.2 days
	158 days	205 days
	71.1°	85.8°
	35.6°	21.7°
	7.2	7
	2.6	4.3
	291 ft.	2443 ft.

Climate

YOU SHOULD KNOW

Many people confuse weather and climate but they are different. Weather is the conditions of the atmosphere over a short period of time, and climate is how the atmosphere is over long periods of time.

Weather is how the atmosphere is behaving and its effects upon life and human activities. Weather can change from minute-to-minute. Most people think of weather in terms of temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure.

Climate is the description of the long-term pattern of weather in a place. Climate can mean the average weather for a particular region and time period taken over 30 years. Climate is the average of weather over time.

August is the hottest month for San Juan County with an average high temperature of 71.8°, which ranks it as one of the coolest places in Washington. In San Juan County, there are 2 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for San Juan County are August, July and June.

In San Juan County, there are 0.2 days annually when the high temperature is over 90°, which is one of the coolest places in Washington.

December has the coldest nighttime temperatures for San Juan County with an average of 34.7°. This is warmer than most places in Washington.

In San Juan County, there are 36.7 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Washington.

In San Juan County, there are 0.0 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Washington.

Humidity in San Juan County is generally quite low and comfortable. There are few days during the summer when the humidity becomes unpleasant. The most humid months (but still comfortable) are August, July and September.

November is the wettest month in San Juan County with 4.6 inches of rain, and the driest month is July with 0.8 inches. The wettest season is Spring with 35% of yearly precipitation and 11% occurs in Autumn, which is the driest season. The annual rainfall of 27.7 inches in San Juan County means that it is drier than most places in Washington.

November is the rainiest month in San Juan County with 17.4 days of rain, and July is the driest month with only 4.9 rainy days. There are 137.9 rainy days annually in San Juan County, which is less rainy than most places in Washington. The rainiest season is Spring when it rains 33% of the time and the driest is Autumn with only a 13% chance of a rainy day.

An annual snowfall of 5.5 inches in San Juan County means that it is about average compared to other places in Washington. December is the snowiest month in San Juan County with 1.8 inches of snow, and 4 months of the year have significant snowfall.