Pai weather in May

In May, Pai sees average daytime highs of 31°C and overnight lows near 21°C, with 193 mm of rain across 20.7 wet days and about 12.9 hours of daylight. It is the 3rd-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 32°C in the first days to 30°C by the end. The sky is clear or mostly clear about 18% of the time in May, and the air most often feels muggy.

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 Pai's 8th-clearest and 5th-windiest month. For the whole year in context, see Pai's year-round climate.

Daytime high
31°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
193 mm
20.7 wet days
Daylight
12 h 54 min
5:55 AM – 6:50 PM
Cloud cover
72%
8th clearest
Wind
5 km/h
5th windiest
Solar energy
5.22 kWh/m²
Travel score
3.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 32°C in the first days to 30°C by the end.

A typical May day in Pai reaches about 31°C in the afternoon and slips back to 21°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 35°C. Set against its neighbours, May runs about 2°C cooler than April and about 2°C warmer than June.

15°20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13221
23221
33221
43221
53221
63221
73221
83221
93221
103121
113121
123121
133121
143121
153121
163121
173121
183122
193122
203122
213122
223122
233122
243022
253022
263022
273022
283022
293022
303022
313022

How May really feels in Pai

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.

Pai 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
Jan27° / 12°162.4118.2
Feb30° / 13°71.411.36.6
Mar32° / 16°213.311.94.8
Apr33° / 20°607.712.43.7
May31° / 21°19320.712.93.3
Jun29° / 22°22125.413.13.1
Jul29° / 22°28727.713.13.2
Aug28° / 21°3212912.73.1
Sep29° / 21°24825.612.13.4
Oct28° / 20°11617.611.64.9
Nov27° / 17°376.611.17.2
Dec26° / 14°163.210.98.2

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% 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 (%)
16139
25941
35743
45545
55347
65149
74951
84753
94456
104357
114060
123961
133664
143466
153367
163070
172971
182773
192674
202575
212476
222278
232179
241981
251981
261882
271783
281783
291585
301486
311486

Chance of precipitation in May

Any precipitation

Pai gets around 193 mm of rain over 20.7 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 66% and peaks near 82% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
149
250
352
453
554
656
757
858
959
1060
1161
1263
1364
1465
1566
1667
1768
1869
1970
2071
2172
2273
2374
2475
2576
2677
2777
2878
2979
3080
3182

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 55% of days. Sticky, muggy-or-worse air turns up on roughly 93% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
15216410
24196512
34186513
43166714
52156716
62146717
71126819
81116721
91106623
10196525
11086428
12076330
13066232
14056134
15055837
16045739
17045541
18035443
19035245
20025147
21024949
22024850
23014653
24014554
25014455
26014257
27004159
28003961
29003862
30003664
31003565

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 6:03 AM to 5:51 AM, and sunset from 6:44 PM to 6:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.76:036:44
212.76:026:45
312.76:016:45
412.76:016:45
512.86:006:46
612.86:006:46
712.85:596:46
812.85:596:47
912.85:586:47
1012.85:586:48
1112.85:576:48
1212.95:576:48
1312.95:566:49
1412.95:566:49
1512.95:566:49
1612.95:556:50
1712.95:556:50
1812.95:546:51
1912.95:546:51
2013.05:546:51
2113.05:536:52
2213.05:536:52
2313.05:536:53
2413.05:536:53
2513.05:526:53
2613.05:526:54
2713.05:526:54
2813.05:526:55
2913.15:526:55
3013.15:526:55
3113.15:516:56

Solar energy in May

Daily solar energy (kWh/m²)

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

For context, solar energy here swings from a low near 3.74 kWh/m² to a high of 6.38 kWh/m² in April across the year — May's 5.22 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.9Bright
25.8Bright
35.8Bright
45.8Bright
55.7Bright
65.7Bright
75.6Bright
85.6Bright
95.5Bright
105.5Bright
115.4Bright
125.4Bright
135.3Bright
145.3Bright
155.2Bright
165.2Bright
175.1Bright
185.1Bright
195.1Bright
205.0Bright
215.0Bright
225.0Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
314.7Bright
Planning a trip in May

Hazard calendar for Pai

In seasonPeak

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

Pai'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 Pai?

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

3.3
Sightseeing
9th-best month of the year
5.0
Beach & pool
8th-best month of the year

May is a weaker month for outdoor sightseeing in Pai.

What to pack for Pai in May

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

In May, Pai sees daytime highs around 31°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

light clothesrain gearsun protection

UV index in Pai in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May 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 Pai peaks around August 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 7 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 12UV 14Dec 22UV 7
UV index (midday)Level
Jan8Very high
Feb10Very high
Mar10Very high
Apr10Extreme
May12Extreme
Jun12Extreme
Jul13Extreme
Aug14Extreme
Sep12Extreme
Oct11Extreme
Nov9Very high
Dec7Very high

Air quality in Pai 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 Pai is worst in March — around 90 µg/m³ PM2.5 (unhealthy), about 9.6× the cleanest month (October, 9 µg/m³).

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

0306090JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyModerateGoodMar 1985 µg/m³Oct 249 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb35Moderate
Mar90Unhealthy
Apr57Unhealthy
May20Moderate
Jun11Good
Jul10Good
Aug10Good
Sep10Good
Oct9Good
Nov9Good
Dec11Good
Location & terrain

Where is Pai?

Pai sits at 19.4°N, 98.4°E, 0 m above sea level, in Thailand. The nearest listed city is Chiang Mai, 86 km away.

San Pa TongSan KamphaengLamphunPa SangLoikawPhayao

Topography around Pai

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

Within 3 km, the terrain around Pai has significant variations in elevation — a maximum elevation change of 444 m around an average of 563 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,543 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,997 m.

The land around Pai is covered by trees (48%), grassland (23%) and cropland (21%) within 3 km, trees (86%) within 16 km, and trees (91%) within 80 km.

3 km
444 m
16 km
1,543 m
80 km
1,997 m
treesgrasslandcroplandartificial surfaces
May weather nearby: Chiang Mai 86 km · Hang Dong 90 km · San Pa Tong 95 km · San Kamphaeng 99 km · Lamphun 105 km · Pa Sang 107 km · Loikaw 134 km · Phayao 152 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 Pai (19.3617°, 98.4397°, elevation 0 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).