# Fine Dust Season in Korea: When It Hits & How to Breathe Easy > When fine dust season hits Korea (spring is worst), how to read AirKorea forecasts, choose KF80/KF94 masks, and keep indoor air clean as a newcomer. Canonical: https://setkora.com/guides/fine-dust-season-korea-guide (also in 13 languages: https://setkora.com/guides//fine-dust-season-korea-guide) If you arrived in Korea in summer or autumn, your first spring can catch you off guard: hazy skies, weather apps glowing orange, and neighbors wearing masks on an otherwise sunny day. That's fine dust season. It peaks from March to May, with episodes through winter, and it's a normal, planned-around part of the calendar here. The good news is that living with it is mostly a routine: check the forecast, wear the right mask on bad days, and keep the air at home clean. Here's when it happens, how to read the alerts, and how to set up your home without a big purchase. ## When fine dust season hits (and why spring is worst) Korea's fine dust (**미세먼지**, misemeonji) is measured in two sizes: PM10 and the smaller PM2.5, which is the one that slips past loose masks and open windows. Levels swing with the seasons, and the pattern is fairly predictable once you know it. - **Spring (March–May): the peak.** Stagnant air, pollution carried in on westerly winds, and spring dust storms often overlap, so this is when you'll see the most orange and red forecast days. - **Winter (December–February)**: heating season adds particles, and cold, still air traps them near the ground, so bad episodes happen here too. - **Summer and early autumn**: monsoon rains and cleaner winds usually wash the air out; this is typically the clearest stretch of the year. - **Yellow dust (황사, hwangsa)**. A separate spring phenomenon: mineral dust blown in from continental deserts. It's tracked in the same forecasts and handled the same way. Mask outside, clean air inside. ## How to check the air: AirKorea and the four grades The official source is **AirKorea (에어코리아)**, run by the national environment agency. Its website and app show real-time readings from monitoring stations near you plus a next-day forecast. Most Korean weather apps, including Naver's and Kakao's, display the same dust grades on their main screen, so you rarely need to go looking. Forecasts use four color-coded grades (the exact colors vary slightly by app): - **좋음 (Good, blue)**: enjoy the outdoors. - **보통 (Moderate, green)**: fine for most people. - **나쁨 (Bad, orange)**: consider limiting long outdoor exercise; many people mask up. - **매우나쁨 (Very bad, red)**: keep outdoor time short and wear a mask. Check both PM10 and **초미세먼지 (PM2.5)**. The finer one matters more for health, and a day can be moderate on one scale while bad on the other. On severe days the government also sends dust alerts to phones through the same channel as weather warnings, so don't be startled the first time your phone buzzes in unison with everyone else's on the subway. ## Masks: what KF80, KF94, and KF99 actually mean Korean dust masks carry a **KF (Korea Filter)** rating certified by the national food and drug safety agency: - **KF80**: filters at least 80% of fine test particles; lighter to breathe through, generally fine for moderate days. - **KF94**: at least 94%; the everyday standard most people reach for on bad dust days. - **KF99**: at least 99%; maximum filtration but noticeably harder to breathe through, so few people wear it daily. You can buy KF masks at any convenience store, pharmacy (약국), Daiso, or online. No need to hunt for them. Two habits make a real difference: press the nose wire so the mask seals (a loose fit leaks air around the filter, which defeats the rating), and treat masks as disposable rather than wearing one for a week. A plain cloth or fashion mask does little against PM2.5, so on orange and red days it's worth grabbing the real thing. ## Keeping indoor air clean at home Indoor air needs a plan too, because dust follows you inside and everyday cooking adds fine particles of its own. - **Ventilate strategically**. On good-air days, open the windows wide and air the place out. On bad days, don't seal yourself in around the clock: short bursts of ventilation, a few minutes a couple of times a day, beat letting cooking fumes and stale air build up. Then run the purifier afterward. - **Use the range hood every time you cook**: frying and grilling can push indoor particle levels above what's outside. - **Damp-mop instead of dry dusting**: a wet cloth traps settled dust instead of launching it back into the air. - **Run an air purifier (공기청정기) with a HEPA-class filter**: sized to your room, it's the biggest single lever for indoor PM2.5. Our [air purifier rental guide](https://setkora.com/guides/rent-air-purifier-korea) covers sizing (purifier capacity vs room area) and filter upkeep in detail. ## Renting an air purifier instead of buying one A decent air purifier is a significant purchase, filters are a recurring cost, and if you're in Korea for a year or two you may not want to own one at the end. That's why many foreign residents rent instead: the cost is spread into a monthly fee without a big upfront purchase, and many rental plans include periodic visits where a technician replaces the filters for you. Exactly the chore that's easiest to forget. Plan details vary by company and model, so it's worth confirming what's included during a consultation. **SETKORA** is a rental brokerage: you apply in any of 13 languages, and the contract itself is signed directly with the manufacturer or rental company, with the Korean-language paperwork and installation scheduling handled for you. Applying is generally possible if you have about a year or more of stay remaining in Korea. The specifics are confirmed in a free consultation. You can [browse air purifiers](https://setkora.com/products?q=air+purifier) to compare models, and if you've just arrived, the [first-month settling-in checklist](https://setkora.com/guides/first-month-in-korea-settling-checklist) covers what else to sort out in your first weeks. ## FAQ **Q: When is fine dust season in Korea?** A: The worst stretch is spring (March through May) when stagnant air, incoming pollution, and yellow dust overlap. Winter also brings bad episodes, while the summer monsoon usually clears the air. AirKorea or any Korean weather app shows day-by-day conditions. **Q: What's the difference between fine dust and yellow dust?** A: Fine dust (미세먼지) refers to pollution particles measured as PM10 and PM2.5, present year-round. Yellow dust (황사) is mineral dust blown in from continental deserts, mainly in spring. Both appear in the same forecasts, and the response is the same: mask outdoors, clean air indoors. **Q: Do I really need an air purifier in Korea?** A: Plenty of people get through dust season with masks and smart ventilation alone, so it isn't mandatory. That said, purifiers are common in Korean households, and if you're sensitive to air quality, work from home, or live near a busy road, one makes bad-air weeks noticeably more comfortable. Renting is a common way to try one without committing to a purchase.