Step into Guangzhou in summer and you’ll instantly feel the heat, humidity, and that familiar threat of rain. Daytime temperatures usually hover around 32–33°C (89–91°F), and nights don’t cool off much, sticking to 24–27°C (75–81°F). The air feels thick, and the humidity mixed with the city’s heat keeps things warm long after dark.
You’ll quickly notice how the weather changes on a dime. One minute, the sun’s out, and the next, a downpour cools everything. Rain peaks from June to August, with heavy showers and thunderstorms that tend to arrive fast but don’t stick around all day. This back-and-forth between heat and rain shapes daily routines, from when you venture outside to when you just need to find some air conditioning.
At the same time, summer in Guangzhou comes with long days and that steady, tropical vibe. Muggy afternoons can feel endless, but sometimes a breeze near the Pearl River brings some relief. If you know what to expect, you can prepare for what to expect and maybe even enjoy the season without too many surprises.
Overview of Summer Weather in Guangzhou
Hot, humid summers in Guangzhou come courtesy of the East Asian monsoon. You’ll see high temperatures, heavy rain early on, and muggy stretches that ease a bit by late summer. The climate keeps things green all year, but summer brings the wildest weather.
Typical Climate Conditions
In summer, you’ll deal with highs around 89–91°F (32°C) and nighttime lows near 78–80°F (26°C). July’s usually the hottest, with highs often breaking 90°F.
Rain falls often in June and July, with monthly averages near 10 inches (250 mm). By August, that drops to about 7 inches (180 mm). Showers hit hard and fast, then leave behind cloudy, humid skies.
Humidity sticks around, with 95–100% of days feeling muggy. You almost never get a break from the sticky air, even after dark. Winds tend to stay gentle, around 6–7 mph, mostly from the south.
Nearby waters heat up too, with surface temps rising from 80°F to 83°F (27–28°C), adding to the muggy feeling.
Köppen Climate Classification
Guangzhou sits in the humid subtropical climate zone (Cfa), according to Köppen. That means hot summers, mild winters, and plenty of rain all year.
What really sets Guangzhou apart from cooler subtropical cities is its powerful summer monsoon. Moist air from the South China Sea brings high humidity and frequent storms. June is usually the wettest month.
Unlike tropical places, Guangzhou does cool off in winter, but summer’s weather dominates most of the year. The city’s spot near the Pearl River Delta and low elevation both crank up the heat and humidity.
Comparison With Other Seasons
If you compare summer to the rest of the year, the difference is obvious. Winters stay mild, with highs around 65°F (18°C) and much lower humidity. Rain barely makes an appearance, so days feel more comfortable.
Spring and autumn are transition times. Spring starts out warm and wet, while autumn cools down and dries out. Many people find these months better for outdoor plans.
Summer, though, drags on as the hottest and most demanding season. It’s a mix of high heat, humidity, and frequent rain, making things less comfy but bearable if you plan, dress light, and use the AC.
Average Summer Temperatures
Guangzhou’s summer is long, hot, and sticky, with little relief day or night. You’ll get steady heat through the whole season, with July and August feeling the worst.
Daytime Highs and Nighttime Lows
Typical summer highs hit about 89°F (32°C). On especially hot days, expect 95–96°F (35–36°C). The humidity makes it feel even hotter, honestly.
Nights offer little relief, with lows around 77–79°F (25–26°C). The muggy air lingers, and nights rarely dip below 72°F (22°C). Most people end up relying on air conditioning to sleep comfortably.
This combo of hot days and warm nights puts Guangzhou among the warmest cities in southern China during summer.
Monthly Temperature Variations
The hot stretch lasts from late May to early October, with the peak in July and August. July averages about 85°F (29°C), with highs near 90–92°F (32–33°C) and lows around 78°F (25°C).
August looks pretty similar, averaging 82–85°F (28–29°C), with highs close to 91°F (33°C). June’s a touch cooler, with highs near 88°F (31°C), but it’s also wetter, so the air feels heavier.
By September, things start easing off, with highs around 87–88°F (31°C). It’s still hot, but you’ll notice shorter days and a slow move toward milder weather.
Record Extremes
Averages tell part of the story, but Guangzhou sometimes sees extreme heat. The hottest summer days can push past 96°F (36°C), especially in late July. It’s rare, but it happens during big heat waves.
Nighttime temps almost never fall below 72°F (22°C) in summer. Unlike northern China, you won’t get big swings between day and night.
These extremes just reinforce that subtropical climate—heat and humidity rule, and cool nights are hard to come by. Anyone visiting or living here should expect steady warmth all summer.
Humidity and Comfort Levels
Summer in Guangzhou means high humidity that really affects how you feel inside and out. Even when temperatures peak, the air’s moisture makes it feel even warmer and less comfortable than you’d think.
Average Relative Humidity
During summer, relative humidity in Guangzhou usually sits between 75% and 95%. The stickiest weather shows up from April through September, with July and August combining the worst heat and highest humidity.
On average, the city hits about 78% humidity year-round, but summer is always higher. For instance, April sees about 84%, while November drops to around 66%—a big difference you’ll feel as soon as you step outside.
High humidity slows down how fast sweat evaporates, so you’ll feel hotter than the thermometer says. A day at 34°C (93°F) with 85% humidity can feel several degrees warmer, especially during the muggiest afternoons.
Impact on Daily Life
You’ll probably notice the humidity most when you’re walking outside or riding the bus. Clothes get damp, and even a short walk can leave you sweaty. Most locals and visitors depend on air conditioning and dehumidifiers to stay comfortable indoors.
You can still do some outdoor sightseeing, but it helps to plan around the heat index. Bring water, wear light, breathable clothes, and take breaks in the shade or indoors with AC.
The moisture also messes with housing and storage. Mold pops up if you leave things in stuffy rooms. Many people use moisture absorbers or keep closets open to reduce dampness.
If you’re visiting, the humidity makes evenings feel warmer than you’d expect, so pack lightweight, quick-dry clothes instead of anything heavy.
Rainfall and Rainy Days
Guangzhou’s summer means lots of rain, plenty of wet days, and a strong monsoon influence. You’ll run into heavy downpours, quick storms, and high humidity that all shape daily routines and travel plans.
Monthly Rainfall Totals
Rain peaks between May and August, with June usually being the wettest month. Monthly totals reach 240–365 mm, which is more than some cities get in a year.
Here’s a quick look:
| Month | Avg Rainfall (mm) |
|---|---|
| May | ~329 |
| June | ~365 |
| July | ~243 |
| August | ~270 |
Most of this rain falls in sudden, heavy bursts—not steady drizzle. Mornings can start clear, then heavy showers roll in by afternoon. This pattern can throw off outdoor plans, especially in June when rain feels endless.
Frequency of Rainy Days
Rainy days matter just as much as the totals. In summer, you’ll get 14–16 rainy days a month, so about half the days have measurable rain.
But it’s not always all-day storms. Showers usually last an hour or two, then leave things humid but dry. Still, the ground can stay wet, and low-lying areas often flood after big bursts.
It’s smart to carry an umbrella or raincoat everywhere. Even if the morning looks fine, you never know what the afternoon brings.
Monsoon Influence
The East Asian summer monsoon drives Guangzhou’s wet season. Warm, moist air from the South China Sea triggers frequent thunderstorms.
The monsoon also pushes humidity above 75%, making hot days feel even hotter. Nights stay muggy since the air barely dries after rain.
From June to September, the monsoon overlaps with typhoon season. Not every year brings a direct hit, but tropical storms can dump hundreds of millimeters of rain in just a few days. Summer is definitely the wettest time in Guangzhou.
Sunshine and Daylight Hours
Summer in Guangzhou brings more direct sun and longer days than any other season. You’ll notice the extra daylight and longer stretches of sunshine, though clouds and rain still pop up.
Average Daily Sunshine Hours
During summer, Guangzhou gets some of its highest sunshine totals. July is usually the sunniest month, with about 6.7 hours of sunshine per day. May and August also bring longer sunny spells, often around 8–9 hours at their peak.
The sunniest period comes in mid-summer when clouds thin out compared to spring. But with rain and humidity sticking around, sunshine hours can swing a lot day to day.
For comparison, Guangzhou logs about 1,629 sunshine hours a year. That’s less than Beijing or Brisbane, but more than cities like Brussels. So, while summer days can be bright, you’ll still want to expect some cloudy stretches.
Longest and Shortest Days
Day length changes slowly through summer. The longest days come in late June, near the summer solstice, with daylight lasting about 13.5 hours. That gives you more time outside, especially in the evenings.
By late August, daylight drops to about 12.5 hours, and by September it’s closer to 12 hours. The change isn’t huge, but you’ll notice less natural light as summer winds down.
Here’s a quick breakdown:
| Month | Approx. Daylight Hours |
|---|---|
| June | 13.5 hours |
| July | 13.3 hours |
| August | 12.8 hours |
You’ll see this steady shift as summer fades into early autumn.
Other Notable Summer Weather Features
Summer in Guangzhou isn’t just about heat and rain. Sun exposure, water temperatures, wind, and air quality all play a part in how you plan your days outside.
UV Index and Sun Protection
Guangzhou’s UV index climbs to very high levels in summer. On clear days, it often peaks between 8 and 11.
With the sun this strong, your skin can burn in under 20 minutes if you skip protection.
It’s best to use broad-spectrum sunscreen (SPF 30 or higher) and reapply every couple of hours. Toss on some protective clothing, too.
A wide-brimmed hat? Definitely helpful. Sunglasses with UV protection are a must, not just a style choice.
The sun hits hardest from 10 a.m. to 3 p.m.. If you’re planning outdoor activities, maybe aim for early morning or late afternoon.
Shade can be tough to find in many parts of the city, so carrying a compact umbrella makes a lot of sense.
Sea and River Temperatures
Water around Guangzhou stays warm all summer. The South China Sea usually sits at 28–29 °C (82–84 °F) from June to August, which feels great for swimming.
Local rivers, like the Pearl River, keep warm too. Still, most people skip swimming there because the water quality isn’t great.
Instead, folks enjoy river cruises, especially after dark when the heat lingers.
If you’re looking to cool off, the coast near Guangzhou has better swimming spots.
Hotel and community pools are everywhere and offer safer options.
Thanks to the warm water, you can leave the wetsuit at home. Just remember to stay hydrated and grab shade breaks when you can.
Wind and Air Quality
In summer, winds usually blow in from the south and southwest. They bring moist air from the sea.
These winds can cool the city a bit, but they also drag in heavy humidity. When thunderstorms roll in or typhoons get close, the winds pick up and feel much stronger.
Air quality tends to be better in summer than in winter. That’s mostly because strong winds scatter pollutants more quickly.
Still, high humidity sometimes makes the air feel thick, and on really sunny days, you might notice ozone levels climbing.
If you’re worried about your breathing, it’s smart to check local air quality reports before heading out for a long stretch. Using air conditioning with filters and staying indoors during peak pollution hours can help you avoid extra exposure.