Climate and average weather in Ayutthaya
In Ayutthaya, the weather is oppressive, sweltering, wet, and partly cloudy and remarkably steady, with daytime highs holding near sweltering levels all year. The wettest stretch peaks around September.
Over the course of the year, the temperature in Ayutthaya typically varies from 22°C to 36°C, and is rarely below 18°C or above 39°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 Ayutthaya for warm-weather activities are from early January to mid February and mid November to late December.
- Hottest
- Apr
- 36°
- Coldest
- Dec
- 22°
- Wettest
- Sep
- 266 mm
- Driest
- Dec
- 8 mm
- Rain / yr
- 1251 mm
- 173 wet days
- Daylight
- 11.2–12.8 h
- shortest–longest
- Elevation
- 7 m
- 14.4°N
- Clearest
- Feb
- 37% cloud
Ayutthaya is city in Phra Nakhon Si Ayutthaya province, Thailand.
- Air quality
- Elevated
- PM10 47.6 µg/m³ · 2017
- Density
- 3,425/km²
- people per km²
- Founded
- 1350
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Ayutthaya 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 mid November to late December.
Temperature through the year
Daily average highs and lows in Ayutthaya, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in Ayutthaya stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 36°C and low of 27°C; the coolest is December, with an average low of 22°C and high of 32°C.
Days typically run about 9°C warmer than nights, with the widest day–night swing (around 11°C) in January.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 33 | 34 | 35 | 36 | 35 | 34 | 34 | 34 | 33 | 33 | 33 | 32 |
| Avg low (°C) | 22 | 23 | 26 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 24 | 22 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 33 | 22 |
| Feb | 34 | 23 |
| Mar | 35 | 26 |
| Apr | 36 | 27 |
| May | 35 | 27 |
| Jun | 34 | 27 |
| Jul | 34 | 26 |
| Aug | 34 | 26 |
| Sep | 33 | 26 |
| Oct | 33 | 25 |
| Nov | 33 | 24 |
| Dec | 32 | 22 |
How hot and cold Ayutthaya really feels
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, Ayutthaya feels like about 45°C (around April 26). Nearly every day a year carries some heat stress, and 240 of them tip into dangerous heat (feels-like above 39°C), peaking in April.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 34 | 37 | 41 | 45 | 44 | 43 | 41 | 41 | 41 | 39 | 36 | 33 |
| Air high (°C) | 33 | 34 | 35 | 36 | 35 | 34 | 34 | 34 | 33 | 33 | 33 | 32 |
| Feels-like low (°C) | 22 | 23 | 26 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 24 | 22 |
| Air low (°C) | 22 | 23 | 26 | 27 | 27 | 27 | 26 | 26 | 26 | 25 | 24 | 22 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 34 | 33 | 22 | 22 |
| Feb | 37 | 34 | 23 | 23 |
| Mar | 41 | 35 | 26 | 26 |
| Apr | 45 | 36 | 27 | 27 |
| May | 44 | 35 | 27 | 27 |
| Jun | 43 | 34 | 27 | 27 |
| Jul | 41 | 34 | 26 | 26 |
| Aug | 41 | 34 | 26 | 26 |
| Sep | 41 | 33 | 26 | 26 |
| Oct | 39 | 33 | 25 | 25 |
| Nov | 36 | 33 | 24 | 24 |
| Dec | 33 | 32 | 22 | 22 |
Average hourly temperature in Ayutthaya
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 36°C, and coldest before dawn in December, near 22°C.
Ayutthaya weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 33° / 22° | 12 | 2.7 | 11.2 | 4.6 |
| Feb | 34° / 23° | 14 | 3.1 | 11.5 | 3.7 |
| Mar | 35° / 26° | 46 | 7.6 | 11.9 | 2.6 |
| Apr | 36° / 27° | 77 | 12.9 | 12.3 | 1.7 |
| May | 35° / 27° | 159 | 22.2 | 12.7 | 1.6 |
| Jun | 34° / 27° | 149 | 23.4 | 12.8 | 1.8 |
| Jul | 34° / 26° | 149 | 23.6 | 12.8 | 2.0 |
| Aug | 34° / 26° | 175 | 24.5 | 12.5 | 2.0 |
| Sep | 33° / 26° | 266 | 25.8 | 12.1 | 2.1 |
| Oct | 33° / 25° | 164 | 19.3 | 11.7 | 2.9 |
| Nov | 33° / 24° | 33 | 5.7 | 11.3 | 4.0 |
| Dec | 32° / 22° | 8 | 2 | 11.2 | 4.7 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Ayutthaya gets about 1251 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 6.0 months, from around Apr 23 to Oct 23, peaking in September at about 87% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 21.
September is the wettest month by volume, with 266 mm over about 26 wet days; December is the driest, with 8 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 8 | 11 | 25 | 43 | 72 | 78 | 76 | 79 | 86 | 61 | 20 | 6 |
| Rain days | 3 | 3 | 8 | 13 | 22 | 23 | 24 | 25 | 26 | 19 | 6 | 2 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 8 | 3 |
| Feb | 11 | 3 |
| Mar | 25 | 8 |
| Apr | 43 | 13 |
| May | 72 | 22 |
| Jun | 78 | 23 |
| Jul | 76 | 24 |
| Aug | 79 | 25 |
| Sep | 86 | 26 |
| Oct | 61 | 19 |
| Nov | 20 | 6 |
| Dec | 6 | 2 |
Monthly rainfall
Over a full year, Ayutthaya collects about 1251 mm of rain across 173 wet days — roughly 104 mm in an average month.
It doesn’t fall evenly. September is the wettest month with 266 mm, while December is the driest at just 8 mm. The three wettest months alone bring about 48% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 12 | 14 | 46 | 77 | 159 | 149 | 149 | 175 | 266 | 164 | 33 | 8 |
| Rain days | 3 | 3 | 8 | 13 | 22 | 23 | 24 | 25 | 26 | 19 | 6 | 2 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 12 | 3 |
| Feb | 14 | 3 |
| Mar | 46 | 8 |
| Apr | 77 | 13 |
| May | 159 | 22 |
| Jun | 149 | 23 |
| Jul | 149 | 24 |
| Aug | 175 | 25 |
| Sep | 266 | 26 |
| Oct | 164 | 19 |
| Nov | 33 | 6 |
| Dec | 8 | 2 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Ayutthaya, 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 21 and lasts for 6.3 months, ending around April 30. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 81% of the time on average.
The cloudier part of the year begins around May 1 and lasts for 5.7 months, ending around October 20. The cloudiest month is August, when it is overcast or mostly cloudy 95% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 73 | 81 | 72 | 53 | 21 | 7 | 8 | 5 | 10 | 35 | 58 | 66 |
| Cloudier (%) | 27 | 19 | 28 | 47 | 79 | 93 | 92 | 95 | 90 | 65 | 42 | 34 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 73 | 27 |
| Feb | 81 | 19 |
| Mar | 72 | 28 |
| Apr | 53 | 47 |
| May | 21 | 79 |
| Jun | 7 | 93 |
| Jul | 8 | 92 |
| Aug | 5 | 95 |
| Sep | 10 | 90 |
| Oct | 35 | 65 |
| Nov | 58 | 42 |
| Dec | 66 | 34 |
Daylight, sunrise and sunset
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 May 27, brings about 12 h 48 min of light; the shortest, around January 1, only 11 h 12 min — a swing of roughly 1 h 36 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.2 | 11.5 | 11.9 | 12.3 | 12.7 | 12.8 | 12.8 | 12.5 | 12.1 | 11.7 | 11.3 | 11.2 |
| Sunrise (AM) | 6:50 | 6:47 | 6:30 | 6:08 | 5:54 | 5:53 | 6:00 | 6:07 | 6:10 | 6:13 | 6:23 | 6:39 |
| Sunset (PM) | 6:04 | 6:18 | 6:24 | 6:28 | 6:34 | 6:43 | 6:47 | 6:36 | 6:14 | 5:53 | 5:43 | 5:49 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 11.2 | 6:50 | 6:04 |
| Feb | 11.5 | 6:47 | 6:18 |
| Mar | 11.9 | 6:30 | 6:24 |
| Apr | 12.3 | 6:08 | 6:28 |
| May | 12.7 | 5:54 | 6:34 |
| Jun | 12.8 | 5:53 | 6:43 |
| Jul | 12.8 | 6:00 | 6:47 |
| Aug | 12.5 | 6:07 | 6:36 |
| Sep | 12.1 | 6:10 | 6:14 |
| Oct | 11.7 | 6:13 | 5:53 |
| Nov | 11.3 | 6:23 | 5:43 |
| Dec | 11.2 | 6:39 | 5:49 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Ayutthaya averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 20 days.
The sunnier stretch runs 6.0 months, from around Oct 24 to Apr 23. The sunniest month is February, with roughly 19 sunny days (bright).
The greyest month is August, down near 0 sunny days — about 98% fewer than the February peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 17 | 18 | 17 | 9 | 3 | 1 | 1 | 0 | 1 | 6 | 11 | 14 |
| Sky | Bright | Bright | Bright | Mixed | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 17 | Bright |
| Feb | 18 | Bright |
| Mar | 17 | Bright |
| Apr | 9 | Mixed |
| May | 3 | Gloomy |
| Jun | 1 | Gloomy |
| Jul | 1 | Gloomy |
| Aug | 0 | Gloomy |
| Sep | 1 | Gloomy |
| Oct | 6 | Gloomy |
| Nov | 11 | Mixed |
| Dec | 14 | Mixed |
Humidity comfort
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 Ayutthaya, how humid it feels changes noticeably over the year.
The more humid part of the year lasts 8.9 months, from around February 18 to November 15. The muggiest month is April, when the air feels humid, muggy or worse about 100% of the time.
The most comfortable stretch runs from around November 16 to February 17, and December is the most comfortable month — the air is dry or comfortable 19% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 4 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 |
| Comfortable (%) | 10 | 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 4 | 13 |
| Humid (%) | 22 | 12 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 12 | 24 |
| Muggy (%) | 27 | 18 | 8 | 3 | 0 | 0 | 0 | 0 | 0 | 6 | 28 | 32 |
| Oppressive (%) | 31 | 46 | 51 | 33 | 16 | 25 | 38 | 41 | 18 | 24 | 33 | 21 |
| Miserable (%) | 6 | 18 | 37 | 64 | 84 | 75 | 62 | 59 | 82 | 67 | 23 | 4 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 4 | 10 | 22 | 27 | 31 | 6 |
| Feb | 2 | 5 | 12 | 18 | 46 | 18 |
| Mar | 0 | 1 | 2 | 8 | 51 | 37 |
| Apr | 0 | 0 | 0 | 3 | 33 | 64 |
| May | 0 | 0 | 0 | 0 | 16 | 84 |
| Jun | 0 | 0 | 0 | 0 | 25 | 75 |
| Jul | 0 | 0 | 0 | 0 | 38 | 62 |
| Aug | 0 | 0 | 0 | 0 | 41 | 59 |
| Sep | 0 | 0 | 0 | 0 | 18 | 82 |
| Oct | 0 | 1 | 2 | 6 | 24 | 67 |
| Nov | 0 | 4 | 12 | 28 | 33 | 23 |
| Dec | 5 | 13 | 24 | 32 | 21 | 4 |
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.
Across the year, average wind speed in Ayutthaya is typically calm, near 9 km/h, and varies little with the seasons.
The windier part of the year lasts 3.5 months, from around May 17 to Aug 30. The windiest month is August, averaging about 10 km/h (calm).
The calmer part of the year runs from around Aug 31 to Nov 20, with October the calmest month at about 7 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 7 | 8 | 9 | 9 | 9 | 9 | 10 | 10 | 7 | 7 | 8 | 9 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 7 | calm |
| Feb | 8 | calm |
| Mar | 9 | calm |
| Apr | 9 | calm |
| May | 9 | calm |
| Jun | 9 | calm |
| Jul | 10 | calm |
| Aug | 10 | calm |
| Sep | 7 | calm |
| Oct | 7 | calm |
| Nov | 8 | calm |
| Dec | 9 | calm |
Hazard calendar for Ayutthaya
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Ayutthaya's monsoon runs May–October, when most of the year's rain falls.
Best time to visit Ayutthaya
To characterize how pleasant the weather is in Ayutthaya throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late November, Ayutthaya 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 Ayutthaya for general outdoor tourist activities is from mid November to mid February, with a peak score in the last week of December.
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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 4.6 | 3.7 | 2.6 | 1.7 | 1.6 | 1.8 | 2.0 | 2.0 | 2.1 | 3.0 | 4.0 | 4.7 |
| Rating | fair | fair | poor | poor | poor | poor | poor | poor | poor | poor | fair | fair |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 4.6 | fair |
| Feb | 3.7 | fair |
| Mar | 2.6 | poor |
| Apr | 1.7 | poor |
| May | 1.6 | poor |
| Jun | 1.8 | poor |
| Jul | 2.0 | poor |
| Aug | 2.0 | poor |
| Sep | 2.1 | poor |
| Oct | 3.0 | poor |
| Nov | 4.0 | fair |
| Dec | 4.7 | fair |
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 Ayutthaya for hot-weather activities is from early November to early March, with a peak score in the last week of December.
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 Ayutthaya, by month
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.
Ayutthaya packs about the same all year — highs hold near 36°C. Across the year the things worth having are light clothes, rain gear and sun protection.
In April, Ayutthaya sees daytime highs around 36°C and nights near 27°C. Pack light clothes and sun protection. Worth having: rain gear. About 13 days see rain.
UV index (midday) in Ayutthaya by month
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 Ayutthaya peaks around August 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 23 at about 8 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 9 | 9 | 12 | 11 | 11 | 12 | 12 | 13 | 12 | 10 | 8 | 8 |
| Level | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 9 | Very high |
| Feb | 9 | Very high |
| Mar | 12 | Extreme |
| Apr | 11 | Extreme |
| May | 11 | Extreme |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 13 | Extreme |
| Sep | 12 | Extreme |
| Oct | 10 | Very high |
| Nov | 8 | Very high |
| Dec | 8 | Very high |
Average hourly UV index in Ayutthaya
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 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 7 | 7 | 7.5 | 7.5 | 8 | 8.5 | 8 | 8 | 8 | 7 | 6.5 | 6.5 |
| UV ≥ 6 (h/day) | 4.5 | 4.5 | 5.5 | 5.5 | 5.5 | 6 | 6 | 6.5 | 6 | 5 | 4 | 4 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 7 | 4.5 |
| Feb | 7 | 4.5 |
| Mar | 7.5 | 5.5 |
| Apr | 7.5 | 5.5 |
| May | 8 | 5.5 |
| Jun | 8.5 | 6 |
| Jul | 8 | 6 |
| Aug | 8 | 6.5 |
| Sep | 8 | 6 |
| Oct | 7 | 5 |
| Nov | 6.5 | 4 |
| Dec | 6.5 | 4 |
Air quality in Ayutthaya by month
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 Ayutthaya is worst in January — around 83 µg/m³ PM2.5 (unhealthy), about 1.9× the cleanest month (July, 43 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 83 | 81 | 70 | 64 | 54 | 44 | 43 | 43 | 54 | 66 | 67 | 66 |
| Level | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Poor | Poor | Poor | Poor | Unhealthy | Unhealthy | Unhealthy |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 83 | Unhealthy |
| Feb | 81 | Unhealthy |
| Mar | 70 | Unhealthy |
| Apr | 64 | Unhealthy |
| May | 54 | Poor |
| Jun | 44 | Poor |
| Jul | 43 | Poor |
| Aug | 43 | Poor |
| Sep | 54 | Poor |
| Oct | 66 | Unhealthy |
| Nov | 67 | Unhealthy |
| Dec | 66 | Unhealthy |
Growing season
Ayutthaya is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
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. Ayutthaya banks about 7,100 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around April.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 533 | 521 | 633 | 651 | 657 | 616 | 621 | 615 | 580 | 585 | 553 | 535 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 533 |
| Feb | 521 |
| Mar | 633 |
| Apr | 651 |
| May | 657 |
| Jun | 616 |
| Jul | 621 |
| Aug | 615 |
| Sep | 580 |
| Oct | 585 |
| Nov | 553 |
| Dec | 535 |
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.
Ayutthaya receives about 5.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.5 and 6.2 kWh/m².
The brighter stretch of the year lasts 4.6 months, from around Jan 27 to Jun 14. The brightest month is April, averaging about 6.1 kWh/m² (intense).
The dimmest month is September, down near 4.5 kWh/m² — roughly 26% less than the April peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.0 | 5.5 | 6.0 | 6.2 | 5.6 | 5.1 | 4.8 | 4.6 | 4.6 | 4.7 | 4.8 | 4.8 |
| Level | Bright | Bright | Bright | Intense | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 5.0 | Bright |
| Feb | 5.5 | Bright |
| Mar | 6.0 | Bright |
| Apr | 6.2 | Intense |
| May | 5.6 | Bright |
| Jun | 5.1 | Bright |
| Jul | 4.8 | Bright |
| Aug | 4.6 | Bright |
| Sep | 4.6 | Bright |
| Oct | 4.7 | Bright |
| Nov | 4.8 | Bright |
| Dec | 4.8 | Bright |
Where is Ayutthaya?
Ayutthaya sits at 14.4°N, 100.6°E, 7 m above sea level, in Thailand. The nearest listed city is Bang Ban, 10 km away.
What Ayutthaya looks like
Topography around Ayutthaya
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ayutthaya.
Within 3 km, the terrain around Ayutthaya has only modest variations in elevation — a maximum elevation change of 13 m around an average of 6 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 40 m; within 80 km, large variations in elevation — a maximum elevation change of 1,097 m.
The land around Ayutthaya is covered by artificial surfaces (38%) and trees (37%) within 3 km, cropland (52%) within 16 km, and cropland (56%) and trees (25%) within 80 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
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 Ayutthaya (14.3517°, 100.5774°, elevation 7 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).