Average Weather in Royal City Washington, United States
In Royal City, the summers are hot, arid, and mostly clear and the winters are short, very cold, dry, and partly cloudy. Over the course of the year, the temperature typically varies from 24°F to 93°F and is rarely below 11°F or above 102°F.
Based on the tourism score, the best time of year to visit Royal City for warm-weather activities is from late June to late August.
The hot season lasts for 3.0 months, from June 12 to September 13, with an average daily high temperature above 81°F. The hottest day of the year is July 30, with an average high of 93°F and low of 61°F.
The cold season lasts for 2.9 months, from November 19 to February 16, with an average daily high temperature below 46°F. The coldest day of the year is December 23, with an average low of 24°F and high of 35°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 Royal City, 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 Royal City begins around June 7 and lasts for 4.0 months, ending around October 9. On August 4, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 82% of the time, and overcast or mostly cloudy 18% of the time.
The cloudier part of the year begins around October 9 and lasts for 8.0 months, ending around June 7. On January 16, the cloudiest day of the year, the sky is overcast or mostly cloudy 66% of the time, and clear, mostly clear, or partly cloudy 34% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Royal City varies throughout the year.
The wetter season lasts 4.6 months, from October 22 to March 9, with a greater than 13% chance of a given day being a wet day. The chance of a wet day peaks at 24% on November 28.
The drier season lasts 7.4 months, from March 9 to October 22. The smallest chance of a wet day is 3% on August 23.
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 Royal City changes throughout the year.
Rain alone is the most common for 11 months, from January 14 to December 24. The highest chance of a day with rain alone is 19% on November 10.
Snow alone is the most common for 3.0 weeks, from December 24 to January 14. The highest chance of a day with snow alone is 10% on December 28.
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. Royal City experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.8 months, from October 12 to June 5, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around November 18, with an average total accumulation of 0.9 inches.
The rainless period of the year lasts for 4.2 months, from June 5 to October 12. The least rain falls around August 15, with an average total accumulation of 0.2 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. Royal City experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 3.3 months, from November 11 to February 21, 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 30, with an average total liquid-equivalent accumulation of 0.5 inches.
The snowless period of the year lasts for 8.7 months, from February 21 to November 11. The least snow falls around July 7, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Royal City varies significantly over the course of the year. In 2018, the shortest day is December 21, with 8 hours, 31 minutes of daylight; the longest day is June 21, with 15 hours, 53 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:03 AM on June 15, and the latest sunrise is 2 hours, 41 minutes later at 7:44 AM on November 3. The earliest sunset is at 4:09 PM on December 10, and the latest sunset is 4 hours, 48 minutes later at 8:57 PM on June 26.
Daylight saving time (DST) is observed in Royal City 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 Royal City, 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
The average hourly wind speed in Royal City experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.0 months, from February 5 to July 6, with average wind speeds of more than 7.3 miles per hour. The windiest day of the year is March 29, with an average hourly wind speed of 7.9 miles per hour.
The calmer time of year lasts for 7.0 months, from July 6 to February 5. The calmest day of the year is October 20, with an average hourly wind speed of 6.7 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Royal City varies throughout the year.
The wind is most often from the west for 6.9 months, from March 5 to October 1, with a peak percentage of 58% on June 22. The wind is most often from the north for 1.2 months, from October 1 to November 7 and for 3.6 months, from November 18 to March 5, with a peak percentage of 35% on October 4. The wind is most often from the south for 1.6 weeks, from November 7 to November 18, with a peak percentage of 31% on November 17.
Best Time of Year to Visit
To characterize how pleasant the weather is in Royal City 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 Royal City for general outdoor tourist activities is from late June 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 Royal City 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 Royal City typically lasts for 6.1 months (186 days), from around April 14 to around October 18, rarely starting before March 28 or after May 3, and rarely ending before September 30 or after November 3.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Royal City should appear around April 7, only rarely appearing before March 28 or after April 19.
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 3.3 months, from May 11 to August 21, with an average daily incident shortwave energy per square meter above 6.4 kWh. The brightest day of the year is July 13, with an average of 7.8 kWh.
The darker period of the year lasts for 3.6 months, from October 27 to February 17, with an average daily incident shortwave energy per square meter below 2.5 kWh. The darkest day of the year is December 23, with an average of 1.2 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Royal City are 46.901 deg latitude, -119.631 deg longitude, and 1,056 ft elevation.
The topography within 2 miles of Royal City contains only modest variations in elevation, with a maximum elevation change of 308 feet and an average elevation above sea level of 1,043 feet. Within 10 miles contains only modest variations in elevation (2,162 feet). Within 50 miles contains large variations in elevation (6,516 feet).
The area within 2 miles of Royal City is covered by cropland (68%) and shrubs (27%), within 10 miles by cropland (51%) and shrubs (42%), and within 50 miles by shrubs (55%) and cropland (34%).
This report illustrates the typical weather in Royal City, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Royal City.
For each station, the records are corrected for the elevation difference between that station and Royal City 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 Royal City is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Royal City and a given station.
The stations contributing to this reconstruction are: Hanford (38%, 37 kilometers, south); Grant County International Airport (34%, 42 kilometers, northeast); Bowers Field (15%, 70 kilometers, west); and Yakima Air Terminal Airport (13%, 79 kilometers, southwest).
Time zones for aiports and weather stations are provided by AskGeo.com .