Cloud cover in a weather forecast indicates how much of the sky is expected to be covered by clouds. It's a measure of cloudiness observed from a specific location.
Understanding Cloud Cover
Cloud cover, also known as cloudiness, cloudage, or cloud amount, represents the fraction of the sky that is, on average, obscured by clouds when viewed from a particular location. It's a crucial element in weather forecasting, affecting temperature, sunshine duration, and precipitation likelihood.
How Cloud Cover is Measured
Cloud cover is typically measured in oktas, which are eighths of the sky. Here's a simple breakdown:
| Oktas | Description | Sky Coverage |
|---|---|---|
| 0 | Clear | 0% |
| 1-2 | Few | 1-25% |
| 3-4 | Scattered | 26-50% |
| 5-7 | Broken | 51-99% |
| 8 | Overcast | 100% |
Impact of Cloud Cover
- Temperature: Clouds can block sunlight during the day, leading to cooler temperatures. At night, clouds can trap heat, resulting in warmer temperatures than on clear nights.
- Sunshine: More cloud cover means less direct sunlight reaching the ground. This affects solar power generation and the amount of UV radiation.
- Precipitation: Cloud cover is a key indicator of potential precipitation. Thick, widespread cloud cover often precedes rain or snow.
Examples of Cloud Cover in Forecasts
- "Partly cloudy": This usually indicates a cloud cover of 3-4 oktas (scattered).
- "Mostly sunny": Suggests a cloud cover of 1-2 oktas (few).
- "Overcast": Means the sky is completely covered with clouds (8 oktas).
