Visibility
How far you can clearly see
What is it?
Visibility is the greatest distance at which objects can be clearly seen and identified. It drops when fog, haze, dust, smoke or heavy precipitation scatter light between you and the horizon.
How we measure it
Horizontal visibility (metres, shown as km/mi) at the current hour from the Open-Meteo forecast.
Visibility bands (met practice)
- > 10 kmClearUnrestricted view; no impact
- 4–10 kmHaze / light mistDistant objects soften; normal driving
- 1–4 kmMistNoticeably reduced; increase following distance
- 200 m–1 kmFogDifficult driving; delays for flights
- < 200 mDense fogHazardous travel; airports disrupted
Within safe range
Above ~10 km the atmosphere is effectively transparent for everyday purposes — travel, sport and aviation operate normally.
Beyond the range
Below ~1 km, reaction distance exceeds sight distance at highway speeds — multi-vehicle pileups happen in exactly these conditions. Below 200 m even walking routes become disorienting, and airports move to low-visibility procedures or close.
Precautions
- In fog: low-beam headlights and fog lamps — high beams reflect back and blind you.
- Slow until you can stop within what you can see; triple following distance.
- Use road-edge markings, not the vehicle ahead, as your guide.
- Never stop in a traffic lane; if you must stop, exit the roadway fully.
- Check visibility before dawn drives — fog is thickest around sunrise.