Average Weather in September in West Side Highway Washington, United States
Daily low temperatures decrease by 5°F, from 52°F to 47°F, rarely falling below 39°F or exceeding 58°F.
For reference, on August 3, the hottest day of the year, temperatures in West Side Highway typically range from 55°F to 79°F, while on January 1, the coldest day of the year, they range from 35°F to 44°F.
Average High and Low Temperature in September
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. The horizontal axis is the day, 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 September
The month of September in West Side Highway experiences rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 32% to 46%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 68% of the time.
For reference, on November 30, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 79%, while on August 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 78%.
Cloud Cover Categories in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In West Side Highway, the chance of a wet day over the course of September is very rapidly increasing, starting the month at 14% and ending it at 27%.
For reference, the year's highest daily chance of a wet day is 61% on November 18, and its lowest chance is 6% on August 3.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in West Side Highway is rapidly increasing, starting the month at 1.3 inches, when it rarely exceeds 2.8 inches or falls below 0.1 inches, and ending the month at 3.1 inches, when it rarely exceeds 6.0 inches or falls below 0.6 inches.
Average Monthly Rainfall in September
Over the course of September in West Side Highway, the length of the day is rapidly decreasing. From the start to the end of the month, the length of the day decreases by 1 hour, 33 minutes, implying an average daily decrease of 3 minutes, 13 seconds, and weekly decrease of 22 minutes, 32 seconds.
The shortest day of the month is September 30, with 11 hours, 44 minutes of daylight and the longest day is September 1, with 13 hours, 18 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in West Side Highway is 6:32 AM on September 1 and the latest sunrise is 37 minutes later at 7:09 AM on September 30.
The latest sunset is 7:49 PM on September 1 and the earliest sunset is 57 minutes earlier at 6:53 PM on September 30.
Daylight saving time is observed in West Side Highway during 2018, but it neither starts nor ends during September, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:20 AM and sets 15 hours, 47 minutes later, at 9:06 PM, while on December 21, the shortest day of the year, it rises at 7:51 AM and sets 8 hours, 37 minutes later, at 4:28 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in West Side Highway is essentially constant during September, remaining around 0% throughout.
For reference, on August 4, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in September
The average hourly wind speed in West Side Highway is essentially constant during September, remaining within 0.1 miles per hour of 3.6 miles per hour throughout.
For reference, on December 4, the windiest day of the year, the daily average wind speed is 5.0 miles per hour, while on August 24, the calmest day of the year, the daily average wind speed is 3.5 miles per hour.
Average Wind Speed in September
Wind Direction in September
West Side Highway is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in West Side Highway is gradually decreasing during September, falling by 2°F, from 58°F to 56°F, over the course of the month.
Average Water Temperature in September
The growing season in West Side Highway typically lasts for 6.8 months (207 days), from around April 10 to around November 3, rarely starting before March 12 or after May 4, and rarely ending before October 13 or after November 26.
The month of September in West Side Highway is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in September
The average accumulated growing degree days in West Side Highway are increasing during September, increasing by 293°F, from 1,474°F to 1,768°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in West Side Highway is rapidly decreasing during September, falling by 1.8 kWh, from 5.4 kWh to 3.6 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of West Side Highway are 46.184 deg latitude, -122.917 deg longitude, and 246 ft elevation.
The topography within 2 miles of West Side Highway contains very significant variations in elevation, with a maximum elevation change of 902 feet and an average elevation above sea level of 238 feet. Within 10 miles contains very significant variations in elevation (2,156 feet). Within 50 miles contains large variations in elevation (8,284 feet).
The area within 2 miles of West Side Highway is covered by trees (36%), artificial surfaces (31%), and herbaceous vegetation (15%), within 10 miles by trees (52%) and shrubs (19%), and within 50 miles by trees (54%) and shrubs (25%).
This report illustrates the typical weather in West Side Highway year round, 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 West Side Highway.
For each station, the records are corrected for the elevation difference between that station and West Side Highway 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 West Side Highway is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between West Side Highway and a given station.
The stations contributing to this reconstruction are: Southwest Washington Regional Airport (82%, 8 kilometers, south); South Lewis County Airport (14%, 34 kilometers, north); and Clatsop County Airport (4.2%, 75 kilometers, west).
Time zones for aiports and weather stations are provided by AskGeo.com .