Average Weather in September in Prineville Oregon, United States
In Prineville, the month of September is characterized by rapidly falling daily high temperatures, with daily highs decreasing by 10°F, from 82°F to 72°F over the course of the month, and rarely exceeding 92°F or dropping below 58°F.
Daily low temperatures decrease by 7°F, from 46°F to 39°F, rarely falling below 30°F or exceeding 54°F.
For reference, on August 3, the hottest day of the year, temperatures in Prineville typically range from 51°F to 88°F, while on December 23, the coldest day of the year, they range from 25°F to 41°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 Prineville experiences rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 24% to 37%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 76% of the time.
For reference, on January 16, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 64%, while on July 28, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 84%.
Cloud Cover in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Prineville, the chance of a wet day over the course of September is increasing, starting the month at 6% and ending it at 11%.
For reference, the year's highest daily chance of a wet day is 32% on November 28, and its lowest chance is 6% on August 14.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Prineville is gradually increasing, starting the month at 0.3 inches, when it rarely exceeds 1.0 inches, and ending the month at 0.6 inches, when it rarely exceeds 1.4 inches or falls below 0.1 inches.
Average Monthly Rainfall in September
Over the course of September in Prineville, 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, 27 minutes, implying an average daily decrease of 3 minutes, 1 second, and weekly decrease of 21 minutes, 5 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, 12 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Prineville is 6:26 AM on September 1 and the latest sunrise is 34 minutes later at 7:00 AM on September 30.
The latest sunset is 7:38 PM on September 1 and the earliest sunset is 54 minutes earlier at 6:45 PM on September 30.
Daylight saving time is observed in Prineville during 2017, 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 5:19 AM and sets 15 hours, 32 minutes later, at 8:51 PM, while on December 21, the shortest day of the year, it rises at 7:36 AM and sets 8 hours, 51 minutes later, at 4:27 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Prineville is essentially constant during September, remaining around 0% throughout.
For reference, on August 14, 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 Prineville is essentially constant during September, remaining within 0.1 miles per hour of 3.3 miles per hour throughout.
For reference, on December 3, the windiest day of the year, the daily average wind speed is 4.8 miles per hour, while on August 10, the calmest day of the year, the daily average wind speed is 3.2 miles per hour.
Average Wind Speed in September
Wind Direction in September
The average daily incident shortwave solar energy in Prineville is rapidly decreasing during September, falling by 1.8 kWh, from 6.2 kWh to 4.4 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 Prineville are 44.300 deg latitude, -120.834 deg longitude, and 3,002 ft elevation.
The topography within 2 miles of Prineville contains significant variations in elevation, with a maximum elevation change of 623 feet and an average elevation above sea level of 2,986 feet. Within 10 miles contains significant variations in elevation (2,343 feet). Within 50 miles contains large variations in elevation (9,229 feet).
The area within 2 miles of Prineville is covered by shrubs (53%), artificial surfaces (28%), and cropland (18%), within 10 miles by shrubs (75%) and cropland (19%), and within 50 miles by shrubs (76%) and trees (19%).
This report illustrates the typical weather in Prineville 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 Prineville.
For each station, the records are corrected for the elevation difference between that station and Prineville 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 Prineville is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Prineville and a given station.
The stations contributing to this reconstruction are: Roberts Field-Redmond Municipal Airport (85%, 25 kilometers, west); John Day State Airport (6%, 149 kilometers, east); The Dalles Municipal Airport (4.7%, 149 kilometers, north); and Burns Municipal Airport (4.6%, 170 kilometers, southeast).
Time zones for aiports and weather stations are provided by AskGeo.com .