- PM2.5 and PM10 readings appear in weather apps and dedicated ones.
- On bad days, shifting to indoor plans is the practical move.
- Masks are sold in convenience stores and pharmacies.
Who this is for
- Anyone looking at a washed-out window and wondering what to do with the day
- People who want their viewpoint or hill day to land on a clear one
- Anyone with a sensitive throat or eyes who’d like the measures sorted in advance
Some mornings the view from the window looks washed out. Fog or pollution? You can’t tell by looking.
In Korea, air quality is treated as everyday information alongside the forecast. People check it, and schools and workplaces sometimes act on it.
“Does that matter to a visitor?” It does. Here’s the thing: whether you check the number can change the quality of the whole day. Let’s get into it.
Your Weather App Is Enough! Where to Find the Number
✔ Most phone weather apps include an air quality field
Allow location access and it shows your current area.
For more detail, environmental agency data or a dedicated app gives an hourly trend and forecast, so you can see whether the afternoon improves or worsens.
Displays in metro stations and public buildings often show it too, so you pass the information as you walk.
| Condition | Roughly | Action |
|---|---|---|
| Good | Low readings | Keep outdoor plans |
| Moderate | Mid range | Limit long stretches outdoors |
| Poor | High | Shift to indoor plans |
| Very poor | Very high | Minimise time outside |
| Where to check | Weather or dedicated apps | Hourly trend available |
| Mitigation | Masks and indoor venues | Pharmacies and convenience stores |
✔ Got this far? Then this is your next move. “Seoul Weather in August and September” is the step after.
Keep a Few Indoor Options in Reserve! Reshuffling the Day
✔ Pushing through a long outdoor day on a high reading leaves you with a sore throat and irritated eyes
Especially if you’re prone to respiratory trouble.
Keeping a few indoor options in reserve makes the switch quick: museums, galleries, underground arcades, large bookshops, cinemas, cafes. Any of them fills half a day.
Conversely, on a clear day with low readings, prioritise viewpoints, hills, and the riverside. The same place looks entirely different.
Autumn brings more clear days than most seasons, but it varies day to day. A one-minute check each morning saves a lot of wasted walking.
Sold at the Convenience Store! Masks and Small Measures
✔ Masks are sold in pharmacies, convenience stores, and drugstores
Including grades rated for fine particles.
Most indoor venues run air purifiers, and some metro carriages have them too.
Drink water, and wash your face and hands when you get back. Simple, but it helps. If your eyes get itchy, eye drops are worth carrying.
Humidity Is the Tell! Telling Fog From Pollution
✔ Autumn mornings can bring radiation fog
That’s not pollution, and it burns off as the sun rises.
The reading is the reliable way to tell. With fog, humidity is high while air quality readings stay low.
If humidity is low but visibility is poor, particles are the likelier explanation.
Even a bad day is rarely bad all day. A wind shift can clear things within hours. Reading the hourly forecast and putting the bad window indoors and the good window outdoors is the smartest approach. One minute, one number, then out the door.
FAQ
Which app should I use?
Most weather apps include air quality. A dedicated app gives finer detail.
Where can I buy masks?
Pharmacies, convenience stores, and drugstores.
Is autumn air good?
More clear days than most seasons, but it varies daily.
Is indoors safe?
Most venues run purifiers, and readings indoors with windows closed are lower.
What about children?
On high-reading days, shifting to indoor plans is the sensible call.
Information as of 2026-09-18 (official listings and Google Maps as shown at publication). Updated when things change.