Average Weather in Sunnyslope Washington, United States
In Sunnyslope, the summers are warm, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 25°F to 89°F and is rarely below 13°F or above 98°F.
Based on the tourism score, the best time of year to visit Sunnyslope for warm-weather activities is from early July to late August.
The hot season lasts for 3.0 months, from June 13 to September 13, with an average daily high temperature above 78°F. The hottest day of the year is August 1, with an average high of 89°F and low of 64°F.
The cold season lasts for 3.0 months, from November 18 to February 20, with an average daily high temperature below 44°F. The coldest day of the year is December 30, with an average low of 25°F and high of 33°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In Sunnyslope, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Sunnyslope begins around June 9 and lasts for 3.9 months, ending around October 6. On August 3, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 81% of the time, and overcast or mostly cloudy 19% of the time.
The cloudier part of the year begins around October 6 and lasts for 8.1 months, ending around June 9. On January 15, the cloudiest day of the year, the sky is overcast or mostly cloudy 65% of the time, and clear, mostly clear, or partly cloudy 35% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Sunnyslope varies significantly throughout the year.
The wetter season lasts 5.3 months, from October 17 to March 26, with a greater than 21% chance of a given day being a wet day. The chance of a wet day peaks at 38% on November 28.
The drier season lasts 6.7 months, from March 26 to October 17. The smallest chance of a wet day is 5% on August 5.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Sunnyslope changes throughout the year.
Rain alone is the most common for 11 months, from January 11 to December 16. The highest chance of a day with rain alone is 33% on November 10.
Snow alone is the most common for 3.7 weeks, from December 16 to January 11. The highest chance of a day with snow alone is 16% on December 27.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Sunnyslope experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 9.4 months, from September 10 to June 23, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around November 17, with an average total accumulation of 2.4 inches.
The rainless period of the year lasts for 2.6 months, from June 23 to September 10. The least rain falls around August 3, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Sunnyslope experiences significant seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 4.4 months, from November 1 to March 14, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around December 31, with an average total liquid-equivalent accumulation of 1.2 inches.
The snowless period of the year lasts for 7.6 months, from March 14 to November 1. The least snow falls around July 17, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Sunnyslope varies significantly over the course of the year. In 2018, the shortest day is December 21, with 8 hours, 27 minutes of daylight; the longest day is June 21, with 15 hours, 58 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:03 AM on June 16, and the latest sunrise is 2 hours, 46 minutes later at 7:49 AM on December 31. The earliest sunset is at 4:10 PM on December 11, and the latest sunset is 4 hours, 52 minutes later at 9:02 PM on June 25.
Daylight saving time (DST) is observed in Sunnyslope during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level in Sunnyslope, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Sunnyslope experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.9 months, from March 8 to September 6, with average wind speeds of more than 5.3 miles per hour. The windiest day of the year is June 20, with an average hourly wind speed of 6.1 miles per hour.
The calmer time of year lasts for 6.1 months, from September 6 to March 8. The calmest day of the year is December 21, with an average hourly wind speed of 4.5 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Sunnyslope varies throughout the year.
The wind is most often from the west for 9.7 months, from February 18 to December 10, with a peak percentage of 71% on June 23. The wind is most often from the north for 2.3 months, from December 10 to February 18, with a peak percentage of 38% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Sunnyslope throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Sunnyslope for general outdoor tourist activities is from early July to late August, with a peak score in the first week of August.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Sunnyslope for hot-weather activities is from mid July to mid August, with a peak score in the first week of August.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Sunnyslope typically lasts for 7.1 months (218 days), from around March 27 to around November 1, rarely starting before March 3 or after April 21, and rarely ending before October 15 or after November 18.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Sunnyslope should appear around April 16, only rarely appearing before April 4 or after April 30.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.2 months, from May 14 to August 21, with an average daily incident shortwave energy per square meter above 6.3 kWh. The brightest day of the year is July 14, with an average of 7.6 kWh.
The darker period of the year lasts for 3.7 months, from October 26 to February 16, with an average daily incident shortwave energy per square meter below 2.4 kWh. The darkest day of the year is December 24, with an average of 1.1 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Sunnyslope are 47.473 deg latitude, -120.337 deg longitude, and 984 ft elevation.
The topography within 2 miles of Sunnyslope contains very significant variations in elevation, with a maximum elevation change of 1,299 feet and an average elevation above sea level of 888 feet. Within 10 miles contains very significant variations in elevation (4,488 feet). Within 50 miles also contains extreme variations in elevation (8,747 feet).
The area within 2 miles of Sunnyslope is covered by artificial surfaces (31%), cropland (25%), shrubs (24%), and grassland (13%), within 10 miles by shrubs (54%) and cropland (13%), and within 50 miles by shrubs (46%) and trees (24%).
This report illustrates the typical weather in Sunnyslope, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Sunnyslope.
For each station, the records are corrected for the elevation difference between that station and Sunnyslope according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Sunnyslope is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sunnyslope and a given station.
Time zones for aiports and weather stations are provided by AskGeo.com .