Cổ Đô weather in May

In May, Cổ Đô sees average daytime highs of 31°C and overnight lows near 25°C, with 230 mm of rain across 17.9 wet days and about 13 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 12% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 48 min at the start of May to 13 h 12 min by month's end. Set against the rest of the year, May is Cổ Đô's 6th-clearest and 3rd-windiest month. For the whole year in context, see Cổ Đô's year-round climate.

Daytime high
31°
4th warmest
Overnight low
25°
8th coldest
Rainfall
230 mm
17.9 wet days
Daylight
13 hours
5:24 AM – 6:25 PM
Cloud cover
76%
6th clearest
Wind
6 km/h
3rd windiest
Solar energy
4.66 kWh/m²
Travel score
3.4
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical May day in Cổ Đô reaches about 31°C in the afternoon and slips back to 25°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 36°C. Set against its neighbours, May runs about 3°C warmer than April and about 2°C cooler than June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13123
23124
33124
43124
53124
63124
73124
83124
93124
103124
113124
123124
133124
143124
153124
163125
173225
183225
193225
203225
213225
223225
233225
243225
253225
263225
273225
283225
293225
303225
313226

How May really feels in Cổ Đô

Once humidity and wind are folded in, May 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
4 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

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

Cổ Đô weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 14°459.110.86.0
Feb21° / 15°348.511.36.3
Mar24° / 18°6111.611.86.3
Apr29° / 22°10312.212.55.2
May31° / 25°23017.9133.4
Jun33° / 26°23819.113.32.6
Jul33° / 26°29120.913.22.6
Aug32° / 26°35422.512.72.7
Sep31° / 25°23018.812.13.5
Oct29° / 22°11911.611.55.6
Nov25° / 19°587.5117.1
Dec21° / 15°387.610.76.8

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 12% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 12% of May, with mostly cloudy or overcast conditions the remaining 75%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23367
33367
43268
53367
63367
73268
83268
93268
103070
113070
122971
132872
142773
152674
162575
172476
182476
192278
202278
212080
222080
231981
241882
251783
261783
271684
281585
291585
301486
311486

Chance of precipitation in May

Any precipitation

Cổ Đô gets around 230 mm of rain over 17.9 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 58% and peaks near 67% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
147
247
348
449
549
650
751
851
952
1053
1154
1255
1356
1457
1558
1658
1759
1860
1961
2061
2162
2263
2363
2464
2565
2666
2766
2866
2967
3067
3167

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the miserable band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
14164138
24164139
33164041
43153942
53153844
63143746
72143647
82143549
92133451
102133352
112133352
122123254
132123155
141123156
151113058
161113058
171112959
181102960
191102861
20192862
21192763
22192763
23082666
24082567
25072469
26062371
27062272
28052174
29052075
30041977
31041878

Wind in May

Winds average 6 km/h in May.

Across May, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 48 min at the start of May to 13 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 24 minutes over May. Sunrise moves from 5:33 AM to 5:20 AM, and sunset from 6:19 PM to 6:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:336:19
212.85:326:19
312.85:316:20
412.85:316:20
512.85:306:20
612.95:296:21
712.95:296:21
812.95:286:22
912.95:286:22
1012.95:276:23
1112.95:276:23
1213.05:266:23
1313.05:266:24
1413.05:256:24
1513.05:256:25
1613.05:246:25
1713.05:246:26
1813.05:246:26
1913.15:236:26
2013.15:236:27
2113.15:236:27
2213.15:226:28
2313.15:226:28
2413.15:226:29
2513.15:216:29
2613.15:216:29
2713.15:216:30
2813.25:216:30
2913.25:216:31
3013.25:206:31
3113.25:206:32

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.66 kWh/m².

For context, solar energy here swings from a low near 2.16 kWh/m² to a high of 4.77 kWh/m² in June across the year — May's 4.66 kWh/m² sits near the top of that range.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.7Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
314.7Bright
Planning a trip in May

Hazard calendar for Cổ Đô

In seasonPeak

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

Cổ Đô sits in the Pacific typhoon belt; the season peaks July–October.

Cổ Đô'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 May a good time to visit Cổ Đô?

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

3.4
Sightseeing
9th-best month of the year
5.2
Beach & pool
5th-best month of the year

May is a weaker month for outdoor sightseeing in Cổ Đô.

What to pack for Cổ Đô in May

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

In May, Cổ Đô sees daytime highs around 31°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 18 days see rain.

light clothesrain gearsun protection

UV index in Cổ Đô in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cổ Đô peaks around June 20 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 20 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highHighVery highExtremeHighJun 20UV 12Nov 20UV 5
UV index (midday)Level
Jan6High
Feb7High
Mar8Very high
Apr6High
May8Very high
Jun12Extreme
Jul11Extreme
Aug11Extreme
Sep6High
Oct7Very high
Nov5High
Dec6High

Air quality in Cổ Đô in May

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Cổ Đô is worst in April — around 98 µg/m³ PM2.5 (unhealthy), about 3.8× the cleanest month (July, 26 µg/m³).

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

0306090120JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyPoorModeratePoorUnhealthyApr 1494 µg/m³Jul 2026 µg/m³
PM2.5 (µg/m³)Level
Jan76Unhealthy
Feb71Unhealthy
Mar76Unhealthy
Apr98Unhealthy
May57Unhealthy
Jun32Moderate
Jul26Moderate
Aug28Moderate
Sep39Poor
Oct53Poor
Nov66Unhealthy
Dec77Unhealthy
Location & terrain

Where is Cổ Đô?

Cổ Đô sits at 21.3°N, 105.4°E, 17 m above sea level, in Vietnam. The nearest listed city is Việt Trì, 6.0 km away.

Topography around Cổ Đô

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

Within 3 km, the terrain around Cổ Đô has only modest variations in elevation — a maximum elevation change of 22 m around an average of 13 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 333 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,211 m.

The land around Cổ Đô is covered by cropland (39%) within 3 km, trees (42%) and cropland (33%) within 16 km, and trees (72%) within 80 km.

3 km
22 m
16 km
333 m
80 km
2,211 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Việt Trì 6.0 km · Phú Thọ 20 km · Sơn Tây 21 km · Ba Vì 22 km · Vĩnh Yên 25 km · Phúc Yên 36 km · Đan Phượng 37 km · Thượng Cát 43 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 Cổ Đô (21.2796°, 105.364°, elevation 17 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). 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).