Average Weather in September in Raleigh Hills Oregon, United States
Daily high temperatures decrease by 9°F, from 80°F to 71°F, rarely falling below 61°F or exceeding 91°F.
Daily low temperatures decrease by 5°F, from 54°F to 49°F, rarely falling below 42°F or exceeding 60°F.
For reference, on August 3, the hottest day of the year, temperatures in Raleigh Hills typically range from 57°F to 83°F, while on December 30, 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 Raleigh Hills experiences rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 28% to 42%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 72% of the time.
For reference, on January 14, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 76%, while on August 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 82%.
Cloud Cover Categories in September
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. In Raleigh Hills, the chance of a wet day over the course of September is very rapidly increasing, starting the month at 12% and ending it at 25%.
For reference, the year's highest daily chance of a wet day is 58% on November 27, and its lowest chance is 4% on August 4.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Raleigh Hills is rapidly increasing, starting the month at 1.0 inches, when it rarely exceeds 2.3 inches, and ending the month at 2.7 inches, when it rarely exceeds 5.4 inches or falls below 0.5 inches.
Average Monthly Rainfall in September
Over the course of September in Raleigh Hills, 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, 31 minutes, implying an average daily decrease of 3 minutes, 8 seconds, and weekly decrease of 21 minutes, 59 seconds.
The shortest day of the month is September 30, with 11 hours, 45 minutes of daylight and the longest day is September 1, with 13 hours, 16 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Raleigh Hills is 6:32 AM on September 1 and the latest sunrise is 36 minutes later at 7:08 AM on September 30.
The latest sunset is 7:48 PM on September 1 and the earliest sunset is 56 minutes earlier at 6:52 PM on September 30.
Daylight saving time is observed in Raleigh Hills 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 5:22 AM and sets 15 hours, 41 minutes later, at 9:03 PM, while on December 21, the shortest day of the year, it rises at 7:48 AM and sets 8 hours, 42 minutes later, at 4:30 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Raleigh Hills is essentially constant during September, remaining around 0% throughout.
For reference, on August 5, 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
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Raleigh Hills is essentially constant during September, remaining within 0.1 miles per hour of 4.4 miles per hour throughout.
For reference, on December 3, the windiest day of the year, the daily average wind speed is 6.2 miles per hour, while on August 23, the calmest day of the year, the daily average wind speed is 4.3 miles per hour.
Average Wind Speed in September
Wind Direction in September
Raleigh Hills 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 Raleigh Hills 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 Raleigh Hills typically lasts for 7.7 months (236 days), from around March 21 to around November 12, rarely starting before February 19 or after April 15, and rarely ending before October 20 or after December 6.
The month of September in Raleigh Hills 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 Raleigh Hills are increasing during September, increasing by 358°F, from 1,798°F to 2,156°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Raleigh Hills is rapidly decreasing during September, falling by 1.8 kWh, from 5.6 kWh to 3.8 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 Raleigh Hills are 45.481 deg latitude, -122.762 deg longitude, and 289 ft elevation.
The topography within 2 miles of Raleigh Hills contains significant variations in elevation, with a maximum elevation change of 558 feet and an average elevation above sea level of 293 feet. Within 10 miles contains significant variations in elevation (1,253 feet). Within 50 miles contains very significant variations in elevation (6,073 feet).
The area within 2 miles of Raleigh Hills is covered by artificial surfaces (89%) and trees (11%), within 10 miles by artificial surfaces (62%) and cropland (17%), and within 50 miles by trees (47%) and cropland (21%).
This report illustrates the typical weather in Raleigh Hills 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Raleigh Hills.
For each station, the records are corrected for the elevation difference between that station and Raleigh Hills 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 Raleigh Hills is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Raleigh Hills and a given station.
The stations contributing to this reconstruction are: Portland-Hillsboro Airport (33%, 16 kilometers, northwest); Portland International Airport (25%, 18 kilometers, northeast); Pearson Airpark (25%, 18 kilometers, northeast); and Aurora State Airport (16%, 26 kilometers, south).
Time zones for aiports and weather stations are provided by AskGeo.com .