Chiang Rai weather in May

In May, Chiang Rai sees average daytime highs of 32°C and overnight lows near 23°C, with 292 mm of rain across 22.8 wet days and about 12.9 hours of daylight. It is the 3rd-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 20% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 42 min at the start of May to 13 h 06 min by month's end. Set against the rest of the year, May is Chiang Rai's 8th-clearest and 5th-windiest month. For the whole year in context, see Chiang Rai's year-round climate.

Daytime high
32°
3rd warmest
Overnight low
23°
8th coldest
Rainfall
292 mm
22.8 wet days
Daylight
12 h 54 min
5:49 AM – 6:45 PM
Cloud cover
69%
8th clearest
Wind
5 km/h
5th windiest
Solar energy
5.46 kWh/m²
Travel score
2.8
out of 10

Chiang Rai is city in Chiang Rai province, Thailand.

Air quality
Very high
PM2.5 37 µg/m³ · 2019
Density
1,294/km²
people per km²
Founded
1936

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical May day in Chiang Rai reaches about 32°C in the afternoon and slips back to 23°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 36°C. Set against its neighbours, May runs about 2°C cooler than April and on par with June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13322
23322
33322
43322
53323
63323
73323
83223
93223
103223
113223
123223
133223
143223
153223
163223
173223
183223
193223
203223
213223
223223
233223
243223
253223
263223
273224
283224
293224
303224
313224

How May really feels in Chiang Rai

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
heat index over the day's high
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.

Chiang Rai weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 14°22310.97.7
Feb31° / 15°132.411.35.9
Mar33° / 18°425.111.94.1
Apr34° / 21°13211.812.43.1
May32° / 23°29222.812.92.8
Jun31° / 24°29726.213.22.5
Jul31° / 24°39828.413.12.6
Aug30° / 24°38328.812.72.6
Sep30° / 23°29525.112.13.0
Oct30° / 22°13917.811.54.4
Nov28° / 18°496.711.16.7
Dec26° / 15°273.710.88.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 20% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 63%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16436
26337
36139
46040
55842
65743
75545
85248
95149
104951
114753
124456
134258
144060
153862
163763
173466
183268
193070
202971
212773
222575
232476
242377
252179
262080
271882
281783
291585
301486
311387

Chance of precipitation in May

Any precipitation

Chiang Rai gets around 292 mm of rain over 22.8 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 73% and peaks near 85% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
159
261
362
463
564
665
766
867
969
1070
1171
1272
1372
1473
1574
1674
1775
1876
1976
2077
2177
2278
2378
2479
2579
2680
2781
2882
2983
3084
3185

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 76% of days. Sticky, muggy-or-worse air turns up on roughly 98% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1331660
2329680
3327691
4325711
5323731
6322741
7320752
8218782
9217792
10216793
11215803
12214804
13213814
14212815
15111826
16111817
17110818
18110818
1919819
20198010
21188011
22187912
23177913
24177814
25077716
26067717
27057619
28057421
29047422
30047224
31037126

Wind in May

Winds average 5 km/h in May.

Across May, daily wind ranges from about 5 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
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 42 min at the start of May to 13 h 06 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 5:56 AM to 5:45 AM, and sunset from 6:39 PM to 6:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:566:39
212.75:566:40
312.75:556:40
412.85:556:40
512.85:546:41
612.85:536:41
712.85:536:42
812.85:526:42
912.85:526:42
1012.95:516:43
1112.95:516:43
1212.95:506:44
1312.95:506:44
1412.95:506:44
1512.95:496:45
1612.95:496:45
1713.05:486:46
1813.05:486:46
1913.05:486:46
2013.05:476:47
2113.05:476:47
2213.05:476:48
2313.05:466:48
2413.05:466:48
2513.05:466:49
2613.15:466:49
2713.15:466:50
2813.15:456:50
2913.15:456:50
3013.15:456:51
3113.15:456:51

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.46 kWh/m².

For context, solar energy here swings from a low near 4.1 kWh/m² to a high of 6.3 kWh/m² in April across the year — May's 5.46 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.0Bright
26.0Bright
35.9Bright
45.9Bright
55.8Bright
65.8Bright
75.8Bright
85.7Bright
95.7Bright
105.7Bright
115.6Bright
125.6Bright
135.5Bright
145.5Bright
155.5Bright
165.4Bright
175.4Bright
185.4Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.2Bright
255.2Bright
265.2Bright
275.2Bright
285.1Bright
295.1Bright
305.1Bright
315.0Bright
Planning a trip in May

Hazard calendar for Chiang Rai

In seasonPeak

In May, Chiang Rai sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

Chiang Rai's monsoon runs May–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 Chiang Rai?

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

2.8
Sightseeing
9th-best month of the year
4.5
Beach & pool
8th-best month of the year

May is a weaker month for outdoor sightseeing in Chiang Rai.

What to pack for Chiang Rai in May

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

In May, Chiang Rai sees daytime highs around 32°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

UV index in Chiang Rai 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 Chiang Rai peaks around July 17 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 7 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highJul 17UV 13Dec 21UV 7
UV index (midday)Level
Jan7Very high
Feb9Very high
Mar9Very high
Apr10Very high
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Chiang Rai 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 Chiang Rai is worst in April — around 142 µg/m³ PM2.5 (unhealthy), about 12.0× the cleanest month (July, 12 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Chiang Rai's WHO annual average of 37 µg/m³.

0306090120150JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyModerateGoodModerateApr 11137 µg/m³Jul 2312 µg/m³
PM2.5 (µg/m³)Level
Jan21Moderate
Feb36Poor
Mar117Unhealthy
Apr142Unhealthy
May34Moderate
Jun14Moderate
Jul12Good
Aug12Good
Sep12Moderate
Oct13Moderate
Nov14Moderate
Dec17Moderate
Location & terrain

Where is Chiang Rai?

Chiang Rai sits at 19.9°N, 99.8°E, 401 m above sea level, in Thailand. The nearest listed city is Mae Chan, 27 km away.

San Kamphaeng

Topography around Chiang Rai

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

Within 3 km, the terrain around Chiang Rai has only modest variations in elevation — a maximum elevation change of 66 m around an average of 398 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 815 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,937 m.

The land around Chiang Rai is covered by artificial surfaces (43%) and trees (36%) within 3 km, trees (52%) and cropland (33%) within 16 km, and trees (70%) and cropland (21%) within 80 km.

3 km
66 m
16 km
815 m
80 km
1,937 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Mae Chan 27 km · Ban Khoan 56 km · Mae Sai 59 km · Tachilek 60 km · Ban Houakhoua 75 km · Phayao 80 km · Dok Kham Tai 85 km · San Kamphaeng 149 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 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 Chiang Rai (19.9086°, 99.8325°, elevation 401 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).