Korea Monsoon Forecast 2026: When It Starts & How to Prepare

Korea's Monsoon Season: What You Need to Know for 2026

Okay, so I'm gonna be real with you — my first monsoon season in Korea caught me completely off guard. I thought I knew rain. I did not know *jangma* (장마). After three years of dealing with it, I'm here to help you prepare way better than I did.

When Does Jangma Start in 2026?

Korea's monsoon season typically starts in late May or early June and lasts until mid-July. For 2026 specifically, meteorologists are predicting the jangma will begin around June 9-15, though this can shift by a week or two depending on atmospheric conditions.

Here's the thing — the Korea Meteorological Administration (KMA) doesn't officially announce the exact start date until about a week before it happens. Check their English website at www.kma.go.kr/eng for the most up-to-date forecast. You can also download the Weather Now app or Weather Channel Korea app, both available in English.

What Actually Happens During Jangma

Unlike sudden rainstorms, jangma is different. It's *relentless*. You get continuous, heavy rain for days — sometimes weeks. I'm talking 50-100mm of rainfall in a single day. The humidity hits around 80-90%, everything gets damp (and I mean *everything*), and outdoor plans basically evaporate.

The upside? Temperatures are usually mild — around 23-26°C (73-79°F) — so it's not unbearably hot. The downside? Your apartment might develop mold if you're not careful.

How to Prepare: The Practical Stuff

Get an air purifier with dehumidifying function — this is non-negotiable. Coupang (쿠팡) has tons of options ranging from 150,000 KRW to 500,000 KRW. Search "제습기" (dehumidifier) or "제습 공기청정기" (dehumidifying air purifier).

Stock up on moisture absorbers — those little silica gel packets. Buy them at Daiso (다이소) for 1,000-2,000 KRW or at any convenience store. Seriously, everywhere.

Waterproof your space — check window seals, especially in older apartments. If water leaks, contact your landlord immediately. Keep a towel handy for windowsills.

Get proper rain gear — those cheap umbrellas from convenience stores (3,000-5,000 KRW) don't cut it. Invest in a quality one from Emart or GU for 20,000-40,000 KRW. Also grab waterproof shoes.

Apps & Resources to Stay Informed

• Weather Now or 날씨 (Naver Weather) — check hourly forecasts
• Naver Map/Kakao Map — both show real-time rainfall intensity
• Korea Meteorological Administration (KMA) alerts — you can set notifications for severe weather warnings

Lifestyle Tips During Jangma

Work from cafes if your apartment feels claustrophobic. Those air-conditioned cafes we all love? They're actually perfect during monsoon season. Check out my previous post on Seoul's best AC cafes if you need recommendations.

Plan indoor activities — museums (many free on certain days), PC bangs (피씨방), jjimjilbangs (찜질방), or cooking classes. Honestly, this is when I finally do those Korean cooking classes I keep putting off.

Don't do laundry unless absolutely necessary — things take forever to dry. And if you do, run a dehumidifier in the room.

The Silver Lining

After jangma ends in mid-July, summer truly begins. The rain stops, humidity drops (slightly),