Climate and average weather in Pai

In Pai, the summers are sweltering, fairly dry, and mostly clear and the winters are warm and mostly clear.

Best: early November to late December

Over the course of the year, the temperature in Pai typically varies from 12°C to 33°C, and is rarely below 9°C or above 37°C. April is the hottest month of the year, while December is the coldest.

Based on the travel score, the best times of year to visit Pai for warm-weather activities are from early January to mid February and early November to late December.

Hottest
Apr
33°
Coldest
Dec
14°
Wettest
Aug
321 mm
Driest
Feb
7 mm
Rain / yr
1541 mm
171 wet days
Daylight
10.8–13.2 h
shortest–longest
Elevation
0 m
19.4°N
Clearest
Feb
21% cloud

Pai weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early November to late December.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Pai, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 2.3 months, from March 1 to May 9, with daily high temperatures above 32°C. The hottest month of the year in Pai is April, with an average high of 33°C and low of 20°C.

The cool season lasts 1.9 months, from November 21 to January 17, with daily high temperatures below 27°C. The coldest month of the year in Pai is December, with an average low of 14°C and high of 26°C.

Days typically run about 11°C warmer than nights, with the widest day–night swing (around 17°C) in February.

10°20°30°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2712
Feb3013
Mar3216
Apr3320
May3121
Jun2922
Jul2922
Aug2821
Sep2921
Oct2820
Nov2717
Dec2614

How hot and cold Pai really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Pai feels like about 34°C (around April 19). About 104 days a year carry some heat stress, peaking in April.

10°15°20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan27271212
Feb30301313
Mar32321616
Apr34332020
May33312121
Jun32292222
Jul31292222
Aug31282121
Sep31292121
Oct30282020
Nov28271717
Dec26261414

Average hourly temperature in Pai

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on April afternoons, near 33°C, and coldest before dawn in December, near 14°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Pai weather by month

Every month at a glance. Click a month for its detailed page.

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

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Pai gets about 1541 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.7 months, from around May 1 to Oct 22, peaking in August at about 95% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 9.

August is the wettest month by volume, with 321 mm over about 29 wet days; February is the driest, with 7 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetAug 4 · 95%Feb 9 · 5%
Rain on a day (%)Rain days
Jan72
Feb51
Mar103
Apr278
May6621
Jun8525
Jul8928
Aug9329
Sep8526
Oct5618
Nov237
Dec113

Monthly rainfall

Over a full year, Pai collects about 1541 mm of rain across 171 wet days — roughly 128 mm in an average month.

It doesn’t fall evenly. August is the wettest month with 321 mm, while February is the driest at just 7 mm. The three wettest months alone bring about 56% of the year’s total.

050100150200250300350JanFebMarAprMayJunJulAugSepOctNovDec16721601932212873212481163716
Rainfall (mm)Rain days
Jan162
Feb71
Mar213
Apr608
May19321
Jun22125
Jul28728
Aug32129
Sep24826
Oct11618
Nov377
Dec163

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Pai, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around October 16 and lasts for 6.7 months, ending around May 7. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 90% of the time on average.

The cloudier part of the year begins around May 8 and lasts for 5.3 months, ending around October 15. The cloudiest month is August, when it is overcast or mostly cloudy 98% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecFeb 25 · 92%Aug 9 · 1%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan8218
Feb9010
Mar8713
Apr7525
May3466
Jun694
Jul397
Aug298
Sep1288
Oct4753
Nov7129
Dec7822

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 13, brings about 13 h 12 min of light; the shortest, around December 13, only 10 h 48 min — a swing of roughly 2 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.07:076:04
Feb11.37:006:21
Mar11.96:406:32
Apr12.46:136:40
May12.95:556:50
Jun13.15:527:01
Jul13.16:007:04
Aug12.76:106:50
Sep12.16:176:24
Oct11.66:255:58
Nov11.16:395:44
Dec10.96:575:48

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Pai averages about 11 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 25 days.

The sunnier stretch runs 6.1 months, from around Oct 29 to May 3. The sunniest month is February, with roughly 24 sunny days (brilliant).

The greyest month is July, down near 0 sunny days — about 100% fewer than the February peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightbrilliantFeb 2625 daysJul 200 days
Sunny daysSky
Jan21Bright
Feb22Brilliant
Mar24Brilliant
Apr18Bright
May6Gloomy
Jun0Gloomy
Jul0Gloomy
Aug0Gloomy
Sep1Gloomy
Oct7Gloomy
Nov15Mixed
Dec18Bright

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Pai, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 7.5 months, from around April 13 to November 25. The muggiest month is May, when the air feels humid, muggy or worse about 99% of the time.

The most comfortable stretch runs from around November 26 to April 12, and February is the most comfortable month — the air is dry or comfortable 88% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecFeb 6 · 89%May 18 · 0%oppressivehumidmuggycomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan48351520
Feb61271110
Mar39352060
Apr42236353
May0175438
Jun0003367
Jul0003367
Aug0002773
Sep0003069
Oct1286524
Nov41735422
Dec26343090

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Wind in Pai is steady company: average speeds sit near 4 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmMar 22 · 6 km/hSep 28 · 4 km/h
Wind speed (km/h)Feels
Jan4calm
Feb5calm
Mar5calm
Apr5calm
May5calm
Jun5calm
Jul5calm
Aug4calm
Sep4calm
Oct4calm
Nov4calm
Dec4calm

Hazard calendar for Pai

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

Best time to visit Pai

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Pai throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid November, Pai is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Pai for general outdoor tourist activities is from early November to mid February, with a peak score in the last week of December.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationDec 23 · 8.5

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan8.1ideal
Feb6.6good
Mar4.8fair
Apr3.8fair
May3.3poor
Jun3.1poor
Jul3.2poor
Aug3.1poor
Sep3.4poor
Oct4.9fair
Nov7.2good
Dec8.2ideal

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Pai for hot-weather activities is from mid November to early April, with a peak score in the second week of February.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationFeb 8 · 9.0

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Pai, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around April (highs near 33°C), the essentials are light clothes and sun protection. In the cold season around December (highs near 26°C), pack light clothes.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In April, Pai sees daytime highs around 33°C and nights near 20°C. Pack light clothes and sun protection. About 8 days see rain.

UV index (midday) in Pai by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

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

Average hourly UV index in Pai

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in August the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan63.5
Feb74.5
Mar75
Apr85.5
May86
Jun8.56.5
Jul8.57
Aug8.56.5
Sep86
Oct7.55
Nov6.54
Dec63

Air quality in Pai by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly 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
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Pai is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Pai banks about 4,989 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around April.

02,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan302
Feb320
Mar438
Apr493
May501
Jun469
Jul466
Aug458
Sep445
Oct433
Nov360
Dec304

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Pai receives about 4.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.6 and 6.5 kWh/m².

The brighter stretch of the year lasts 4.3 months, from around Jan 17 to May 28. The brightest month is April, averaging about 6.3 kWh/m² (intense).

The dimmest month is August, down near 3.8 kWh/m² — roughly 40% less than the April peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerdimmoderatebrightintenseApr 36.5 kWhAug 73.6 kWh
Solar energy (kWh/m²)Level
Jan4.8Bright
Feb5.7Bright
Mar6.4Intense
Apr6.4Intense
May5.2Bright
Jun4.4Bright
Jul3.9Moderate
Aug3.7Moderate
Sep4.2Bright
Oct4.4Bright
Nov4.4Bright
Dec4.3Bright

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
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).