Hong Kong records about 2382mm of rain across roughly 137 wet days a year, which is a 38% chance on an average day. August is the wettest month at 432mm (18% of the annual total) and December the driest at 27mm. Local rain type: monsoon. Essential from April through September. The typhoon season brings extreme rain. Winter is dry and pleasant. Hong Kong MTR and covered walkways make navigating rain manageable.
Chance of rain on an average day: 38%
Rainfall climatology for Hong Kong. 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 | 2382mm |
| Rain days per year | 137 |
| Odds on an average day | 38% |
| Wettest month | August — 432mm over 26 days |
| Driest month | December — 27mm over 2 days |
| Rain type | monsoon |
| Best dry window | October through December offers clear skies, low humidity, and comfortable temperatures. |
| Worst rain window | August brings torrential monsoon rain — over 430mm in a single month. |
August delivers 1500% more rain than December (432mm vs 27mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 18% of the annual total, so rain in Hong Kong is spread through the year — there is no season you can rely on being dry.
Hong Kong rain arrives in short, heavy bursts — shelter and timing matter more than gear.
Rain falls on about 26 days in August against 2 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 | 33mm | 2 | 7% | 18°C |
| February | 38mm | 2 | 7% | 18°C |
| March | 67mm | 4 | 13% | 20°C |
| April | 137mm | 8 | 27% | 23°C |
| May | 290mm | 18 | 60% | 27°C |
| June | 376mm | 23 | 77% | 30°C |
| July | 374mm | 23 | 77% | 32°C |
| August | 432mm | 26 | 87% | 32°C |
| September | 328mm | 20 | 67% | 30°C |
| October | 100mm | 6 | 20% | 27°C |
| November | 37mm | 2 | 7% | 23°C |
| December | 27mm | 2 | 7% | 20°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Hong Kong 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.
Hong Kong records rain on roughly 137 days a year — about a 38% chance on any given day — totalling around 2382mm.
August, with about 432mm over 26 rain days. That is 18% of the entire year's rainfall in a single month.
December is the driest month at 27mm across roughly 2 days. October through December offers clear skies, low humidity, and comfortable temperatures.
Essential from April through September. The typhoon season brings extreme rain. Winter is dry and pleasant. Hong Kong MTR and covered walkways make navigating rain manageable.
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.