Weather in Hong Kong in May

How May compares

May is the 5th warmest month of the year in Hong Kong and ranks 42nd of 134 destinations we compare for May - see where else is hot in May. Against London's average high of 16.6°C in May, Hong Kong is 11.1°C warmer by day and 15.7°C warmer at night.

Daytime and night-time in May

The typical May day in Hong Kong peaks at 27.7°C, but that is an average: the warmest 10% of days reach 29.8°C or more. About 93% of days top 25°C and 1 in 14 pass 30°C. Nights average 24.0°C; one night in ten drops to 21.8°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest May day here reached 32.2°C (2018-05-23) and the coldest night 17.6°C (1999-05-07).

Rain in May

Wet (more than 8 rainy days): about 20 days with 1 mm or more, 233 mm in total. Year to year it varies a lot - the wettest May was 2015 with 396 mm, the driest 1991 with 80 mm. Humidity averages 87%.

Sea temperature in May

The sea averages 25.5°C - warm enough to swim (22°c+). Depending on the year it ranges from 24.7°C to 26.2°C. For the warmest sea here, come in August (28.5°C).

Sunshine and daylight

Around 3.0 hours of sunshine a day (estimated from cloud cover), 13.1 hours of daylight: the sun rises about 05:44 and sets about 18:56 local time in mid-May. Average cloud cover is 77%.

Is May a good time to visit Hong Kong?

It is a reasonable choice: hot days but expect showers. The best months for Hong Kong on our scoring are November, October, September; months averaging 25°C or more: Apr, May, Jun, Jul, Aug, Sep, Oct.

Expect heat that stays with you into the evening

The main adjustment from a British May is the combination of warmth and humidity, not simply the afternoon temperature. Humidity averages 87%, so favour loose, breathable clothing and leave room for breaks rather than filling every day with walking. Temperatures reach 25°C on 93% of days, making warm-weather packing a sensible default. Plan more demanding outdoor time away from midday, and carry water when you head out. Evenings are still warm, so don't rely on sunset to make the weather feel cool. A light layer may be useful indoors, but heavy clothing is unlikely to earn its place in your luggage.

Keep plans flexible for rain and limited sunshine

Rain is a central part of the decision, not a minor packing detail. With about 20 rainy days, a tightly scheduled trip built around being outdoors is a poor fit for May. Carry a compact umbrella and choose footwear you can tolerate getting wet; a heavy waterproof coat may feel uncomfortable in the humidity. Sunshine averages about 3.0 hours within 13.1 hours of daylight, so long days do not mean long stretches of sun. Keep indoor alternatives available and move outdoor plans around the weather. May works better if you can change direction without feeling that the day has been wasted.

Warm water is a plus, but sunshine is the compromise

The sea averages 25.5°C, making swimming a realistic part of a May trip rather than something reserved for unusually warm days. If comfortable water matters more to you than clear skies, that is a useful reason to consider the month. Pack swimwear, but keep swimming plans flexible around the weather rather than making them the centre of every day. For the trip overall, May is best suited to travellers who tolerate humid heat and do not mind adapting their plans. If your dates are flexible, November, October and September are stronger choices overall; May's warm sea comes with a clear wet-weather trade-off.