Phayao weather in May

In May, Phayao sees average daytime highs of 34°C and overnight lows near 25°C, with 166 mm of rain across 19.7 wet days and about 12.9 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 34°C through the month. The sky is clear or mostly clear about 22% 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 Phayao's 8th-clearest and 4th-windiest month. For the whole year in context, see Phayao's year-round climate.

Daytime high
34°
3rd warmest
Overnight low
25°
10th coldest
Rainfall
166 mm
19.7 wet days
Daylight
12 h 54 min
5:50 AM – 6:44 PM
Cloud cover
70%
8th clearest
Wind
7 km/h
4th windiest
Solar energy
5.48 kWh/m²
Travel score
2.4
out of 10

Phayao is town in Phayao province, Thailand.

Air quality
Elevated
PM2.5 18 µg/m³ · 2019
Founded
1938

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 34°C through the month.

A typical May day in Phayao reaches about 34°C in the afternoon and slips back to 25°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 37°C. Set against its neighbours, May runs about 2°C cooler than April and about 1°C warmer than June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13524
23524
33525
43525
53425
63425
73425
83425
93425
103425
113425
123425
133425
143425
153425
163425
173425
183425
193425
203425
213425
223325
233325
243325
253325
263325
273325
283325
293325
303325
313325

How May really feels in Phayao

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.

Phayao weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 16°152.5116.8
Feb32° / 17°61.211.35.2
Mar35° / 20°283.911.93.4
Apr35° / 24°719.512.42.4
May34° / 25°16619.712.92.4
Jun33° / 25°14421.513.12.4
Jul32° / 25°22124.8132.5
Aug31° / 25°25326.412.72.6
Sep32° / 24°2082312.12.8
Oct31° / 23°9814.711.64.1
Nov30° / 20°31511.16.0
Dec28° / 17°162.410.97.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 13% of May, with mostly cloudy or overcast conditions the remaining 65%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16337
26238
36040
45842
55743
65446
75248
85149
94852
104555
114357
124159
133862
143763
153466
163367
173169
182971
192773
202575
212476
222278
232179
241981
251981
261783
271783
281684
291585
301486
311486

Chance of precipitation in May

Any precipitation

Phayao gets around 166 mm of rain over 19.7 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 63% and peaks near 75% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
149
250
351
451
552
653
754
856
957
1058
1160
1261
1362
1463
1564
1665
1765
1866
1967
2068
2168
2269
2370
2471
2571
2672
2772
2873
2974
3074
3175

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 79% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1129700
2127711
3125731
4123751
5121771
6119791
7118792
8116812
9115822
10113833
11112843
12111844
13110854
1419855
1519846
1618847
1718847
1807858
1907849
20078310
21078211
22078112
23078013
24077914
25067915
26067717
27067618
28057520
29057421
30057322
31047323

Wind in May

Winds average 7 km/h in May.

Across May, daily wind ranges from about 6 km/h on the calmest days to 7 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
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

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 5:57 AM to 5:46 AM, and sunset from 6:38 PM to 6:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:576:38
212.75:566:39
312.75:566:39
412.75:556:39
512.85:556:40
612.85:546:40
712.85:546:40
812.85:536:41
912.85:536:41
1012.85:526:42
1112.85:526:42
1212.95:516:42
1312.95:516:43
1412.95:506:43
1512.95:506:43
1612.95:506:44
1712.95:496:44
1812.95:496:45
1912.95:496:45
2013.05:486:45
2113.05:486:46
2213.05:486:46
2313.05:476:47
2413.05:476:47
2513.05:476:47
2613.05:476:48
2713.05:476:48
2813.05:466:49
2913.05:466:49
3013.15:466:49
3113.15:466:50

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.48 kWh/m².

For context, solar energy here swings from a low near 4.08 kWh/m² to a high of 6.36 kWh/m² in April across the year — May's 5.48 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.0Intense
26.0Bright
36.0Bright
45.9Bright
55.9Bright
65.8Bright
75.8Bright
85.8Bright
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
285.2Bright
295.1Bright
305.1Bright
315.1Bright
Planning a trip in May

Hazard calendar for Phayao

In seasonPeak

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

Phayao sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

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

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

Is May a good time to visit Phayao?

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

2.4
Sightseeing
10th-best month of the year
4.6
Beach & pool
8th-best month of the year

May is a weaker month for outdoor sightseeing in Phayao.

What to pack for Phayao in May

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

In May, Phayao sees daytime highs around 34°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

light clothesrain gearsun protection

UV index in Phayao 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 Phayao peaks around August 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 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 highAug 12UV 13Dec 18UV 7
UV index (midday)Level
Jan8Very high
Feb9Very high
Mar9Very high
Apr10Very high
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Phayao 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 Phayao is worst in March — around 51 µg/m³ PM2.5 (poor), about 5.9× the cleanest month (July, 9 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Phayao's WHO annual average of 18 µg/m³.

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateGoodModerateMar 2049 µg/m³Jul 199 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb23Moderate
Mar51Poor
Apr39Poor
May16Moderate
Jun9Good
Jul9Good
Aug9Good
Sep9Good
Oct10Good
Nov11Good
Dec13Moderate
Location & terrain

Where is Phayao?

Phayao sits at 19.2°N, 99.9°E, 409 m above sea level, in Thailand. The nearest listed city is Dok Kham Tai, 12 km away.

San KamphaengChiang MaiNanMae ChanLampangLamphun

Topography around Phayao

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

Within 3 km, the terrain around Phayao has only modest variations in elevation — a maximum elevation change of 61 m around an average of 402 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,289 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,796 m.

The land around Phayao is covered by trees (33%) and water (30%) within 3 km, cropland (45%) and trees (44%) within 16 km, and trees (77%) within 80 km.

3 km
61 m
16 km
1,289 m
80 km
1,796 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Dok Kham Tai 12 km · Chiang Rai 80 km · San Kamphaeng 94 km · Chiang Mai 104 km · Nan 105 km · Mae Chan 106 km · Lampang 108 km · Lamphun 114 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 Phayao (19.192°, 99.8788°, elevation 409 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).