What Is Mostly Cloudy?
Mostly cloudy is a sky condition where clouds cover most of the visible sky, but some areas remain clear. It falls between partly cloudy and completely overcast conditions.
The amount, type and thickness of the clouds can vary considerably. Mostly cloudy skies may consist of a widespread cloud layer with occasional breaks or numerous individual clouds covering much of the sky.
Mostly cloudy does not necessarily mean rain or snow is expected. Clouds can cover most of the sky without producing precipitation, although cloud cover may increase as a weather system approaches.
Related Conditions
| Condition | Description |
|---|---|
| Overcast | A sky condition where clouds cover nearly all or all of the visible sky. |
| Broken Clouds | A cloud layer that covers much of the sky while leaving noticeable openings between clouds. |
| Mostly Clear | A sky condition where most of the sky is clear and only a relatively small amount of cloud is present. |
| Variable Cloudiness | Conditions where the amount of cloud cover changes noticeably over a relatively short period. |
| High Cloud Cover | Widespread clouds occurring higher in the atmosphere, sometimes allowing sunlight to remain visible through them. |
Related Alerts
| Alert | Description |
|---|---|
| Rainfall Warning | Warns when significant rainfall is expected to reach warning criteria. |
| Snowfall Warning | Warns when significant snowfall is expected to reach warning criteria. |
| Severe Thunderstorm Watch | Indicates that conditions are favourable for the development of severe thunderstorms. |
| Freezing Drizzle Advisory | Issued when freezing drizzle is expected to create icy and hazardous surfaces. |
| Winter Storm Watch | Indicates that hazardous winter weather may develop and could reach warning criteria. |
What Causes Mostly Cloudy Skies?
Mostly cloudy skies develop when enough moisture and rising air are present to produce widespread clouds, but the clouds do not completely cover the sky.
This can occur as a weather system approaches or moves through an area. Air rising along fronts can cool and condense into clouds, causing cloud cover to gradually increase. Depending on the system, skies may progress from mostly clear or partly cloudy to mostly cloudy and eventually overcast.
Cloud cover can also develop when moist air moves into a region or when daytime heating causes pockets of warm air to rise. These processes can create numerous clouds while still leaving occasional openings between them.
Wind at different levels of the atmosphere can continuously move and reshape clouds, causing the amount of visible blue sky to change throughout the day. As a result, mostly cloudy conditions can sometimes alternate with shorter periods of partly cloudy or overcast skies.
FAQ
This is when clouds cover most of the visible sky, although some openings or areas of clear sky remain.
Mostly cloudy conditions still have noticeable breaks in the cloud cover. Overcast generally means essentially the entire sky is covered by clouds.
It means clouds occupy the majority of the sky, while partly cloudy conditions have a larger proportion of clear sky.
No. Mostly cloudy describes the amount of cloud cover rather than whether precipitation will occur. Rain can develop under mostly cloudy skies, but clouds can also remain dry.