Understanding Weather Forecast Terminology: A Step-by-Step Guide

Interpreting weather forecasts can be challenging due to the specialized terminology used. This guide provides a step-by-step breakdown of common weather terms to help you understand forecasts more clearly.
1. Sky Conditions
Sky conditions describe the amount of cloud cover in the atmosphere. Common terms include:
- Clear/Sunny: 1/8 or less of the sky is covered by clouds.
- Mostly Clear/Mostly Sunny: 1/8 to 3/8 cloud cover.
- Partly Cloudy/Partly Sunny: 3/8 to 5/8 cloud cover.
- Mostly Cloudy: 5/8 to 7/8 cloud cover.
- Cloudy: 7/8 to 8/8 cloud cover.
These terms help you gauge how much of the sky is obscured by clouds. (weather.gov)
2. Temperature
Forecasts often provide temperature ranges to indicate expected conditions:
- Around 50/Near 50: Temperatures ranging from 48°F to 52°F.
- Lower 50s: Temperatures between 50°F and 54°F.
- Mid 50s: Temperatures between 53°F and 57°F.
- Upper 50s: Temperatures between 56°F and 59°F.
These ranges provide a more precise expectation of the day's temperatures. (weather.gov)
3. Wind
Wind forecasts include direction and speed, often described as:
- Light Wind: 0-5 mph.
- Breezy: 15-25 mph.
- Windy: 20-30 mph.
- Very Windy: 30-40 mph.
- Strong/Dangerous: Over 40 mph.
These descriptors help you prepare for outdoor activities based on expected wind conditions. (weather.gov)
4. Precipitation Probability
The likelihood of precipitation is expressed as a percentage:
- 0%: No precipitation expected.
- 10%: Slight chance, often termed "isolated."
- 20%: Slight chance, termed "isolated."
- 30-50%: Chance, termed "scattered."
- 60-70%: Likely, termed "numerous."
- 80-100%: Very likely, termed "occasional" or "periods of."
Understanding these percentages helps you assess the likelihood of rain or snow during the forecast period. (weather.gov)
5. Special Weather Events
Forecasts may also mention specific weather events, such as:
- Thundery Showers: Precipitation from cumulonimbus clouds accompanied by thunder and lightning.
- Hazy: Suspension of particulate matter in the air, causing reduced visibility.
- Fair: Generally sunny with few clouds and no occurrence of rain or showers.
These terms provide additional context for unusual or noteworthy weather conditions. (weather.gov.sg)
6. Reading a Forecast Example
Consider a forecast for Los Angeles, CA:
"Thursday, June 18: Clouds yielding to sun; a nice afternoon for the soccer match, High: 75°F (24°C), Low: 62°F (16°C)."
This indicates that the day will start with clouds but will become sunny, with pleasant temperatures suitable for outdoor activities.
7. Utilizing Forecasts Effectively
Understanding these terms allows you to plan your day accordingly, whether it's choosing appropriate clothing or scheduling outdoor events.
For more detailed information on weather terminology, refer to the National Weather Service's glossary. (weather.gov)
By familiarizing yourself with these terms, you can interpret weather forecasts more accurately and make informed decisions based on expected conditions.
Highlights:
- Forecast Terms
- National Weather Service Terminology
- Learn | Forecasting The Weather - Weather Information Portal