The expected sky

Forecast weather symbols

The small marks used to say what the sky is expected to do.

A forecast icon is a summary, not a measurement. It says what a service expects the sky to do in a named period: this hour, this afternoon, tonight. The World Weather Information Service publishes a table for city forecasts and current conditions, and it switches to a night drawing when the local time is night. Rain, showers, drizzle, snow, sleet, hail, fog, mist, haze, and smoke are separate rows in that table. They are not synonyms with different type weights. The Met Office, on its own forecast guide, treats a chance of precipitation as a separate number from the symbol. A 70 percent chance means a 7 in 10 chance that at least a small amount falls in the period. It does not mean the rain icon is 70 percent full. Apple’s Weather app publishes yet another list, including sunrise and sunset, and groups freezing rain with sleet and wintry mix. That grouping is Apple’s. It is labeled as Apple’s on the pages where it matters. None of these drawings is the station-model sign for the same word, and none of them is the emoji.

Day and night are part of the symbol, not a skin. The World Weather Information Service says so. A clear day and a clear night are different pictures. So are a shower and rain. The percentage beside the icon is a third thing.

Start here. Clear sky. Clear sky is the forecast mark a reader meets first, and the night version is a different picture.

1. 1
   
   Clear skyA forecast icon for an expected open sky. Not the alchemical sun, and not a clear night.
2. 2
   
   Clear nightA forecast icon for an expected clear sky after dark. Not the moon, and not a sunny day.
3. 3
   
   Partly cloudyA forecast icon for sun and cloud together. Not overcast, and not a station-model sky circle.
4. 4
   
   Cloudy and overcastForecast icons for a covered sky. Cloudy and overcast are not the same row, and neither is rain.
5. 5
   
   RainA forecast icon for rain expected in a period. Not a shower, not drizzle, and not the station-model sign.
6. 6
   
   Rain showerA forecast icon for rain that starts and ends. Not steady rain, and not a thunderstorm.
7. 7
   
   DrizzleA forecast icon for very small, close-set drops. Not light rain, and not mist.
8. 8
   
   Freezing rainA forecast icon for rain that freezes on contact. Not sleet, and not ordinary rain.
9. 9
   
   SnowA forecast icon for expected snow. Not a snow shower, not sleet, and not a snowman.
10. 10
    
    Snow showerA forecast icon for snow that starts and stops. Not a steady snow icon.
11. 11
    
    SleetA forecast icon publishers label sleet. Not snow, not freezing rain, and not one universal mixture.
12. 12
    
    HailA forecast icon for hail. Not snow, and not sleet.
13. 13
    
    ThunderstormA forecast icon for thunder and lightning. Not a decorative bolt, and not ordinary rain.
14. 14
    
    FogA forecast icon for fog. Not mist, not haze, and not the fog character.
15. 15
    
    MistA forecast icon for mist. Thinner than fog, and not drizzle.
16. 16
    
    HazeA forecast icon for haze. Not fog, not mist, and not smoke.
17. 17
    
    WindA forecast icon for expected wind. Not a wind barb, and not the wind-face character.
18. 18
    
    DustA forecast icon for dust in the air. Not haze, and not a dust storm at the station.
19. 19
    
    SmokeA forecast icon for smoke. Not haze, and not fog.
20. 20
    
    SunriseA weather-app mark for the time the sun is expected to rise. Not a clear-sky forecast.
21. 21
    
    SunsetA weather-app mark for the time the sun is expected to set. Not a sky condition.