2016年7月5日 · When 1/8 to 1/4 of the sky is covered by clouds, it's classified as mostly sunny, or mostly clear at night, according to the NWS. Sunny or clear means there are no clouds in the sky, and...

2025年1月5日 · Ever wondered about the difference between 'mostly sunny' and 'partly cloudy'? It’s more than mindset—it’s about cloud cover and oktas! Learn what these weather terms really mean, backed by NOAA standards.

A forecast of "Partly Cloudy" or "Partly Sunny", is made when between 3/10 and 6/10 of the sky is to be covered with clouds. The difference between these terms is based on the forecast period itself - during the day, either term could be used.

"Scattered" clouds (3/8 to 4/8 cloud coverage) correspond to a partly cloudy or partly sunny sky, with "broken" clouds (5/8 to 7/8 cloud coverage) describing a partly cloudy or partly sunny (5/8 coverage) to mostly cloudy (6/8 to 7/8 coverage) sky.

2024年1月8日 · Mostly clear or mostly sunny is reported for coverage from 1 to 3 oktas, while partly cloudy or partly sunny refers to cloud coverage of 3 to 5 oktas. Mostly cloudy is reported if 5 to 7 oktas of the sky are covered with opaque clouds.

2021年9月13日 · So during the day, a "partly sunny" sky is indeed sunnier than a "mostly cloudy" sky, which psychologically jives as well. "Partly sunny" seems a bit less gloomy than "mostly cloudy," even if you think about it from an English perspective where they should technically mean the same thing.

Partly Cloudy: About 30% to 70% of the sky is covered with clouds BUT usually refers to sky conditions at night. Partly Sunny: About 30% to 70% of the sky is covered with clouds BUT refers only to sky conditions in the daytime.