Rainfall in Tokyo: How Much and When?

Yes, Tokyo receives substantial rainfall: ~1,470 mm (58 in) annually.

Seasonal Pattern

• Rainy Season (Tsuyu): Early June – mid-July. Persistent drizzle, overcast, high humidity. ~300–400 mm.
• Typhoon Season: August–October. Tropical cyclones bring torrential rain (100–300 mm/day), wind, flood risk.
• Autumn Rains: September–October (stationary front).
• Winter: Driest (Dec–Feb ~50 mm/month); occasional snow flurries.
• Spring: Moderate; cherry-blossom season (late Mar) often showery.

Annual Distribution

Wettest months: June, September, October. Driest: December, January.

Urban Impact

• Massive drainage infrastructure (Metropolitan Area Outer Underground Discharge Channel).
• Real-time radar: JMA AMeDAS.
• Carry compact umbrella year-round.