Ít Ong weather in May

In May, Ít Ong sees average daytime highs of 29°C and overnight lows near 21°C, with 109 mm of rain across 16.5 wet days and about 13 hours of daylight. It is the 1st-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 19% of the time in May, and the air most often feels muggy.

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 Ít Ong's 8th-clearest and 6th-windiest month. For the whole year in context, see Ít Ong's year-round climate.

Daytime high
29°
1st warmest
Overnight low
21°
9th coldest
Rainfall
109 mm
16.5 wet days
Daylight
13 hours
5:29 AM – 6:31 PM
Cloud cover
70%
8th clearest
Wind
4 km/h
6th windiest
Solar energy
5.03 kWh/m²
Travel score
4.5
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical May day in Ít Ong reaches about 29°C in the afternoon and slips back to 21°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 32°C. Set against its neighbours, May runs about 1°C warmer than April and about 1°C warmer than June.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12921
22921
32921
42921
52921
62921
72921
82921
92921
102921
112921
122921
132921
142921
152921
162921
172921
182922
192922
202922
212922
222922
232922
242922
252922
262922
272922
282922
292922
302922
312922

Ít Ong weather by month

How May compares with the rest of the year at a glance. May is the 1st-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan20° / 12°263.810.87.4
Feb23° / 13°163.211.38.1
Mar26° / 16°26511.87.8
Apr28° / 19°35812.56.3
May29° / 21°10916.5134.5
Jun28° / 22°24423.813.33.6
Jul28° / 22°39725.613.23.8
Aug28° / 22°42826.212.73.7
Sep28° / 21°23520.812.14.5
Oct26° / 19°619.411.56.7
Nov24° / 16°283.7118.1
Dec21° / 12°233.510.77.7

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 66%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15545
25446
35347
45347
55248
65149
74951
84852
94654
104456
114357
124159
133961
143862
153664
163466
173268
183070
192971
202773
212575
222278
232179
242080
251981
261783
271783
281585
291486
301387
311288

Chance of precipitation in May

Any precipitation

Ít Ong gets around 109 mm of rain over 16.5 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 53% and peaks near 69% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
136
237
337
438
539
640
741
843
944
1045
1147
1248
1349
1450
1552
1653
1754
1856
1957
2059
2160
2262
2363
2464
2565
2665
2766
2867
2968
3069
3169

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the muggy band about 66% of days. Sticky, muggy-or-worse air turns up on roughly 83% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1630631
2628642
3627652
4626662
5624673
6523693
7522694
8520705
9519706
10518716
11416737
12415738
134147210
144137211
154127212
163117214
173107215
18397117
19387118
20287020
21276922
22276724
23276526
24166528
25166231
26166033
27155836
28155638
29045541
30045343
31035146

Wind in May

Winds average 4 km/h in May.

Across May, daily wind ranges from about 4 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

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 5:38 AM to 5:25 AM, and sunset from 6:25 PM to 6:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:386:25
212.85:376:25
312.85:366:25
412.85:366:26
512.95:356:26
612.95:356:27
712.95:346:27
812.95:336:27
912.95:336:28
1012.95:326:28
1112.95:326:29
1213.05:316:29
1313.05:316:30
1413.05:306:30
1513.05:306:30
1613.05:296:31
1713.05:296:31
1813.15:296:32
1913.15:286:32
2013.15:286:33
2113.15:286:33
2213.15:276:34
2313.15:276:34
2413.15:276:34
2513.15:266:35
2613.25:266:35
2713.25:266:36
2813.25:266:36
2913.25:256:37
3013.25:256:37
3113.25:256:37

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.03 kWh/m².

For context, solar energy here swings from a low near 3.04 kWh/m² to a high of 5.19 kWh/m² in April across the year — May's 5.03 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.1Bright
145.1Bright
155.1Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
204.9Bright
214.9Bright
224.9Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.8Bright
284.7Bright
294.7Bright
304.7Bright
314.7Bright
Planning a trip in May

Hazard calendar for Ít Ong

In seasonPeak

None of Ít Ong's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Ít Ong's monsoon runs June–September, when most of the year's rain falls.

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

Is May a good time to visit Ít Ong?

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

4.5
Sightseeing
8th-best month of the year
5.9
Beach & pool
6th-best month of the year

May is a reasonable time to visit Ít Ong for sightseeing.

What to pack for Ít Ong in May

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

In May, Ít Ong sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 17 days see rain.

light clothesrain gearsun protection

UV index in Ít Ong in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ít Ong peaks around June 20 at about 14 (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 highExtremeExtremeVery highHighJun 20UV 14Dec 19UV 6
UV index (midday)Level
Jan7High
Feb9Very high
Mar12Extreme
Apr10Very high
May11Extreme
Jun14Extreme
Jul13Extreme
Aug13Extreme
Sep9Very high
Oct9Very high
Nov8Very high
Dec6High

Air quality in Ít Ong 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 Ít Ong is worst in April — around 70 µg/m³ PM2.5 (unhealthy), about 4.5× the cleanest month (July, 16 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyModeratePoorApr 1169 µg/m³Jul 2016 µg/m³
PM2.5 (µg/m³)Level
Jan43Poor
Feb48Poor
Mar64Unhealthy
Apr70Unhealthy
May34Moderate
Jun18Moderate
Jul16Moderate
Aug17Moderate
Sep23Moderate
Oct30Moderate
Nov37Poor
Dec42Poor
Location & terrain

Where is Ít Ong?

Ít Ong sits at 21.5°N, 104.0°E, 206 m above sea level, in Vietnam. The nearest listed city is Sơn La, 24 km away.

SapaYên BáiDien Bien PhuMường Lay

Topography around Ít Ong

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

Within 3 km, the terrain around Ít Ong has large variations in elevation — a maximum elevation change of 913 m around an average of 362 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,314 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,884 m.

The land around Ít Ong is covered by trees (52%) and grassland (33%) within 3 km, trees (64%) and grassland (27%) within 16 km, and trees (72%) and grassland (23%) within 80 km.

3 km
913 m
16 km
2,314 m
80 km
2,884 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Sơn La 24 km · Thị Trấn Thuận Châu 36 km · Nghĩa Lộ 51 km · Thị Trấn Phố Lu 91 km · Sapa 93 km · Yên Bái 94 km · Dien Bien Phu 105 km · Mường Lay 107 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 Ít Ong (21.5175°, 104.027°, elevation 206 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. 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).