How Long Does Visibility Take to Recover After a Typhoon? 6 Typhoons, 25 Sites
2026-03-10
Every diver dreads typhoon season. But how badly does a typhoon actually hurt visibility — and how long does it take to recover? We analyzed 6 major Japan typhoons and 25 dive sites with over 46,000 real observations to find out.
Key Findings
- Worst visibility: 2–4 days after typhoon passage (not during the storm itself)
- Pacific coast sites (Izu, Kii Peninsula) see -3 to -7m drops
- Sea of Japan sites (Echizen) see minimal impact (-1m or less)
- Ryukyu Islands (Yonaguni) sometimes improve after typhoons
- Recovery: 1 week for most sites; some take 2–3 weeks
The 6 Typhoons We Analyzed
| Typhoon | Date | Before (2wk avg) | After 1 week | After 2 weeks | Change |
|---|---|---|---|---|---|
| Typhoon Hagibis | 2019-10-12 | 12.2m | 9.9m | 10.2m | -2.3m |
| Typhoon Jebi | 2018-09-04 | 12.8m | 11.7m | 13.1m | -0.3m |
| Typhoon Nanmadol | 2022-09-18 | 12.2m | 10.4m | 12.5m | -0.6m |
| Typhoon Khanun | 2023-08-08 | 13.4m | 12.4m | 12.5m | -0.9m |
| Typhoon Shanshan | 2024-08-29 | 15.8m | 14.5m | 15.3m | -0.9m |
| Typhoon Faxai | 2019-09-09 | 12.0m | 12.8m | 13.0m | +0.9m |
Case Study: Typhoon Hagibis (Worst Hit)
Typhoon Hagibis made landfall on October 12, 2019 — one of the strongest typhoons to hit Japan in decades. Here's what happened to visibility day by day across 15 sites:
Note that visibility on day +1 was still relatively high (15.7m) because few shops were open and reporting. The real crash came on day +2 (6.9m). Recovery progressed steadily but was still incomplete at 2 weeks.
Site-by-Site Impact (Hagibis)
| Site | Before | After 1 week | Change |
|---|---|---|---|
| Kashiwajima | 11.8m | 5.0m | -6.8m |
| Kushimoto | 12.0m | 6.0m | -6.0m |
| Mikomoto | 17.5m | 12.5m | -5.0m |
| Akinohama | 18.0m | 13.1m | -4.9m |
| Osezaki Offshore | 11.6m | 7.5m | -4.1m |
| Kumomi | 13.9m | 11.8m | -2.1m |
| Echizen | 9.3m | 8.0m | -1.3m |
| IOP | 9.7m | 9.0m | -0.7m |
| Futo | 9.0m | 8.7m | -0.3m |
| Yonaguni | 23.8m | 28.3m | +4.6m |
Why Do Some Sites Recover Faster?
- Open coast exposure: Sites facing the Pacific directly (Kushimoto, Kashiwajima) take the brunt of wave-stirred sediment.
- Bay enclosure: Enclosed bays trap turbid water longer; open coasts flush faster.
- Kuroshio proximity: Sites near the Kuroshio Current flush quickly. Yonaguni actually improves — the typhoon-driven upwelling brings clearer offshore water.
- Freshwater runoff: After Hagibis' record rainfall, rivers carried massive sediment loads into coastal sites for 2+ weeks.
Practical Guide: When to Dive After a Typhoon
- Days 0–4: Avoid diving at Pacific coast sites
- Days 5–7: Check conditions; some sites recovering
- Days 7–14: Most sites back to normal for small-medium typhoons
- After major typhoon + heavy rain: Allow 2–3 weeks, especially near rivers
- Sea of Japan / Okinawa: Generally 3–5 days sufficient
Use our visibility forecast map or site forecasts to check real-time predicted visibility after typhoon events.
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