Cát Bà weather in July

In July, Cát Bà sees average daytime highs of 30°C and overnight lows near 28°C, with 303 mm of rain across 19.8 wet days and about 13.1 hours of daylight. It is the 1st-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 13% of the time in July, and the air most often feels miserable.

Daylight stretches from about 13 h 12 min at the start of July to 13 hours by month's end. Set against the rest of the year, July is Cát Bà's 11th-clearest and 1st-windiest month. For the whole year in context, see Cát Bà's year-round climate.

Daytime high
30°
1st warmest
Overnight low
28°
12th coldest
Rainfall
303 mm
19.8 wet days
Daylight
13 h 06 min
5:23 AM – 6:32 PM
Cloud cover
80%
11th clearest
Wind
18 km/h
1st windiest
Solar energy
5.22 kWh/m²
Travel score
3.6
out of 10

Cát Bà is town in Vietnam.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical July day in Cát Bà reaches about 30°C in the afternoon and slips back to 28°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 32°C. Set against its neighbours, July runs on par with June and on par with August.

25°28°30°33°35°151015202531
Avg high (°C)Avg low (°C)
13028
23028
33028
43028
53028
63028
73028
83028
93028
103028
113028
123028
133028
143028
153028
163028
173028
183028
193028
203028
213028
223028
233028
243028
253028
263028
273028
283028
293028
303028
313028

How July really feels in Cát Bà

Once humidity and wind are folded in, July averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in July is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Cát Bà weather by month

How July compares with the rest of the year at a glance. July is the 1st-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 16°407.610.96.2
Feb19° / 17°235.711.36.4
Mar21° / 19°407.611.96.6
Apr25° / 23°527.712.57.0
May28° / 26°18515.5135.1
Jun30° / 28°21517.813.23.7
Jul30° / 28°30319.813.13.6
Aug30° / 27°3992412.73.3
Sep29° / 26°3052012.14.0
Oct28° / 25°13411.611.56.2
Nov24° / 21°568.4117.2
Dec21° / 18°396.310.86.9

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in July.

Beyond those clear spells, partly cloudy skies cover about 7% of July, with mostly cloudy or overcast conditions the remaining 80%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11981
22080
32080
42080
52080
62179
72278
82278
92278
102278
112278
122179
132179
142179
151981
162080
172080
182080
191981
202080
212080
222080
232080
242080
252080
262080
272080
282179
292179
302278
312278

Chance of precipitation in July

Any precipitation

Cát Bà gets around 303 mm of rain over 19.8 wet days in July. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 64% and peaks near 73% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
163
263
363
462
562
662
762
861
961
1061
1160
1260
1360
1460
1560
1661
1762
1862
1963
2064
2164
2265
2366
2467
2568
2669
2770
2871
2972
3073
3173

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

Most of July feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, July lands in the miserable band about 99% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
1199
2199
3298
4298
5298
6298
7298
8298
9298
10298
11298
12298
13298
14199
15199
16199
17199
18199
190100
200100
210100
220100
230100
240100
250100
260100
270100
280100
290100
300100
310100

Wind in July

Winds average 18 km/h in July, the windiest month of the year.

Across July, daily wind ranges from about 15 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
119light breeze
219light breeze
319light breeze
419light breeze
519light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3015light breeze
3115light breeze

Sunrise & sunset in July

DaylightNight

Daylight runs from about 13 h 12 min at the start of July to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over July. Sunrise moves from 5:18 AM to 5:29 AM, and sunset from 6:32 PM to 6:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.25:186:32
213.25:186:33
313.25:186:33
413.25:196:33
513.25:196:33
613.25:196:33
713.25:206:33
813.25:206:33
913.25:206:33
1013.25:216:33
1113.25:216:32
1213.25:226:32
1313.25:226:32
1413.25:226:32
1513.25:236:32
1613.15:236:32
1713.15:236:32
1813.15:246:31
1913.15:246:31
2013.15:256:31
2113.15:256:31
2213.15:256:30
2313.15:266:30
2413.15:266:30
2513.05:276:29
2613.05:276:29
2713.05:276:29
2813.05:286:28
2913.05:286:28
3013.05:286:27
3113.05:296:27

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 5.22 kWh/m².

For context, solar energy here swings from a low near 2.74 kWh/m² to a high of 5.4 kWh/m² in May across the year — July's 5.22 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.4Bright
95.4Bright
105.4Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.2Bright
175.2Bright
185.2Bright
195.2Bright
205.1Bright
215.1Bright
225.1Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
295.0Bright
304.9Bright
314.9Bright
Planning a trip in July

Hazard calendar for Cát Bà

In seasonPeak

In July, Cát Bà sits inside its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.

Cát Bà sits in the Pacific typhoon belt; the season peaks July–October.

Cát Bà's monsoon runs May–September, when most of the year's rain falls.

Pacific typhoon
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is July a good time to visit Cát Bà?

Our two travel scores rate July for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.6
Sightseeing
11th-best month of the year
5.0
Beach & pool
7th-best month of the year

July is a weaker month for outdoor sightseeing in Cát Bà.

What to pack for Cát Bà in July

From July's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In July, Cát Bà sees daytime highs around 30°C and nights near 28°C. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

light clothesrain gearsun protection

Sea temperature near Cát Bà in July

The nearest coast averages about 30°C in July — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 14 km away) is warmest in August at about 30°C and coldest in February near 20°C.

It's comfortable for a long swim from Mar 6 to Jan 18 — about 10.5 months when the water holds above 20°C.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan20Refreshing
Feb20Cool
Mar20Refreshing
Apr23Refreshing
May27Warm
Jun29Tropical
Jul30Tropical
Aug30Tropical
Sep29Tropical
Oct28Warm
Nov25Warm
Dec22Refreshing

UV index in Cát Bà in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cát Bà peaks around July 12 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 6 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highHighJul 12UV 12Dec 19UV 6
UV index (midday)Level
Jan7High
Feb8Very high
Mar9Very high
Apr8Very high
May10Extreme
Jun12Extreme
Jul12Extreme
Aug9Very high
Sep9Very high
Oct9Very high
Nov7High
Dec6High

Air quality in Cát Bà in July

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where July falls, not just the annual average.

Air quality in Cát Bà is worst in January — around 42 µg/m³ PM2.5 (poor), about 2.6× the cleanest month (July, 16 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorJan 2342 µg/m³Jul 1716 µg/m³
PM2.5 (µg/m³)Level
Jan42Poor
Feb42Poor
Mar41Poor
Apr40Poor
May26Moderate
Jun19Moderate
Jul16Moderate
Aug18Moderate
Sep21Moderate
Oct27Moderate
Nov29Moderate
Dec39Poor
Location & terrain

Where is Cát Bà?

Cát Bà sits at 20.7°N, 107.0°E, 24 m above sea level, in Vietnam. The nearest listed city is Ha Long, 25 km away.

Topography around Cát Bà

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Cát Bà.

Within 3 km, the terrain around Cát Bà has only modest variations in elevation — a maximum elevation change of 205 m around an average of 22 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 299 m; within 80 km, large variations in elevation — a maximum elevation change of 1,180 m.

The land around Cát Bà is covered by water (58%) and trees (36%) within 3 km, water (80%) within 16 km, and water (51%) and trees (29%) within 80 km.

3 km
205 m
16 km
299 m
80 km
1,180 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
July weather nearby: Ha Long 25 km · Đố Sơn 27 km · Cẩm Phả 39 km · Haiphong 41 km · Cẩm Phả Mines 41 km · Thành Phố Uông Bí 45 km · Kiến An 45 km · Thị Trấn Mạo Khê 60 km

Vietnam travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C / F
220 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,066
2025
Happiness
6.4 / 10
World Happiness, 2025
Safe drinking water
59%
of population, 2024
Homicide rate
1.5
per 100k, 2011
Road deaths
30.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 500
Religion
none 86%Catholic 6%Buddhist 6%Protestant 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Cát Bà (20.7278°, 107.0482°, elevation 24 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).