September 21st, 2026 Timelapse
On September 21st, conditions began in the morning with a predominantly overcast sky that featured nearly complete cloud cover, averaging 99.2%. Low clouds dominated the scene, accounting for 83% of the total cloud cover, while high clouds contributed to 47%. Surface winds were gentle, averaging just 3.5 mph, and winds aloft at 100 meters were slightly stronger at 4.8 mph. This soft breeze and the heavy cloud presence resulted in a cool temperature of approximately 53.1°F, creating a rather somber start to the day. The gentle surface winds and the slightly stronger upper winds indicated minimal turbulence, but the disparity in speed could have created some light wind shear, leading to subtle variations in cloud movement as low clouds moved sluggishly beneath the faster high clouds.
As noon approached, conditions evolved significantly. The sky maintained its thick cloud cover, with a complete 100% cloud coverage observed. The low clouds diminished to just 15.5%, suggesting a shift in the cloud dynamics, while high clouds filled the sky entirely. Winds at the surface increased slightly to 4.6 mph, while winds at 100 meters rose to 6.2 mph, continuing to indicate a stable environment. The light surface winds allowed for the high clouds to drift more freely, moving at a quicker pace than the lower layers, which were nearly absent. This contrast created a visually striking effect, as the high clouds swept across the sky, seemingly in a rush while the atmosphere below remained calm. Even with no precipitation recorded, the dense cloud layers showcased a typical feature of the region’s late summer weather.
By the evening, the winds picked up more noticeably, with surface speeds averaging 9.2 mph and 14.1 mph at 100 meters. The cloud cover also began to shift, dropping to 63.4% overall, with low clouds practically vanishing to just 2.6%. The high clouds, however, remained prominent, accounting for 62.2% of the sky. This change in the cloud makeup, along with the stronger winds, likely contributed to some turbulence, especially as winds aloft continued to clash with the lighter surface winds. As the temperature edged up to around 63.8°F, the evening skies presented a less cluttered yet layered appearance, with the remaining high clouds gliding gracefully across the fading light of the day. The dynamic interplay of wind and cloud movements throughout the day painted a picture of Northwest skies that are ever-changing, yet remarkably serene.
September 21st, 2026 Timeline
Screenshots with weather data (wind layers, clouds, precipitation)
Weather Info for September 21st, 2026
Sunset: 7:11 PM