Yokohama records about 1688mm of rain across roughly 108 wet days a year, which is a 30% chance on an average day. September is the wettest month at 210mm (12% of the annual total) and December the driest at 51mm. Local rain type: monsoon. Yokohama shares Tokyo's rainy season pattern. The harbor area creates additional moisture — carry an umbrella from June through October.
Chance of rain on an average day: 30%
Rainfall climatology for Yokohama. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 1688mm |
| Rain days per year | 108 |
| Odds on an average day | 30% |
| Wettest month | September — 210mm over 15 days |
| Driest month | December — 51mm over 4 days |
| Rain type | monsoon |
| Best dry window | November through January offers the driest, clearest conditions. |
| Worst rain window | June through October brings tsuyu and typhoon season. |
September delivers 312% more rain than December (210mm vs 51mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 12% of the annual total, so rain in Yokohama is spread through the year — there is no season you can rely on being dry.
Yokohama rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 15 days in September against 4 in December — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 52mm | 4 | 13% | 10°C |
| February | 56mm | 4 | 13% | 10°C |
| March | 118mm | 8 | 27% | 13°C |
| April | 125mm | 9 | 30% | 17°C |
| May | 138mm | 10 | 33% | 23°C |
| June | 168mm | 12 | 40% | 27°C |
| July | 154mm | 11 | 37% | 30°C |
| August | 168mm | 12 | 40% | 30°C |
| September | 210mm | 15 | 50% | 27°C |
| October | 197mm | 14 | 47% | 23°C |
| November | 93mm | 7 | 23% | 17°C |
| December | 51mm | 4 | 13% | 13°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Yokohama we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Yokohama records rain on roughly 108 days a year — about a 30% chance on any given day — totalling around 1688mm.
September, with about 210mm over 15 rain days. That is 12% of the entire year's rainfall in a single month.
December is the driest month at 51mm across roughly 4 days. November through January offers the driest, clearest conditions.
Yokohama shares Tokyo's rainy season pattern. The harbor area creates additional moisture — carry an umbrella from June through October.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.