Climate and average weather in Den Chai
In Den Chai, the summers are muggy, sweltering, showery, and mostly clear and the winters are hot and mostly clear.
Over the course of the year, the temperature in Den Chai typically varies from 16°C to 36°C, and is rarely below 12°C or above 40°C. April is the hottest month of the year, while December is the coldest.
Based on the travel score, the best time of year to visit Den Chai for warm-weather activities is from late November to early February.
- Hottest
- Apr
- 36°
- Coldest
- Dec
- 17°
- Wettest
- Aug
- 341 mm
- Driest
- Feb
- 10 mm
- Rain / yr
- 1641 mm
- 167 wet days
- Daylight
- 10.9–13.1 h
- shortest–longest
- Elevation
- 159 m
- 18.0°N
- Clearest
- Feb
- 25% cloud
Den Chai 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 late November to early February.
Temperature through the year
Daily average highs and lows in Den Chai, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in Den Chai 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 24°C; the coolest is December, with an average low of 17°C and high of 29°C.
Days typically run about 10°C warmer than nights, with the widest day–night swing (around 15°C) in February.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 30 | 33 | 35 | 36 | 34 | 32 | 31 | 31 | 31 | 31 | 31 | 29 |
| Avg low (°C) | 16 | 18 | 21 | 24 | 25 | 25 | 25 | 24 | 24 | 23 | 20 | 17 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 30 | 16 |
| Feb | 33 | 18 |
| Mar | 35 | 21 |
| Apr | 36 | 24 |
| May | 34 | 25 |
| Jun | 32 | 25 |
| Jul | 31 | 25 |
| Aug | 31 | 24 |
| Sep | 31 | 24 |
| Oct | 31 | 23 |
| Nov | 31 | 20 |
| Dec | 29 | 17 |
How hot and cold Den Chai 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, Den Chai feels like about 41°C (around April 19). About 296 days a year carry some heat stress, and 83 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) | 31 | 33 | 37 | 41 | 41 | 40 | 38 | 38 | 39 | 37 | 33 | 30 |
| Air high (°C) | 30 | 33 | 35 | 36 | 34 | 32 | 31 | 31 | 31 | 31 | 31 | 29 |
| Feels-like low (°C) | 16 | 18 | 21 | 24 | 25 | 25 | 25 | 24 | 24 | 23 | 20 | 17 |
| Air low (°C) | 16 | 18 | 21 | 24 | 25 | 25 | 25 | 24 | 24 | 23 | 20 | 17 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 31 | 30 | 16 | 16 |
| Feb | 33 | 33 | 18 | 18 |
| Mar | 37 | 35 | 21 | 21 |
| Apr | 41 | 36 | 24 | 24 |
| May | 41 | 34 | 25 | 25 |
| Jun | 40 | 32 | 25 | 25 |
| Jul | 38 | 31 | 25 | 25 |
| Aug | 38 | 31 | 24 | 24 |
| Sep | 39 | 31 | 24 | 24 |
| Oct | 37 | 31 | 23 | 23 |
| Nov | 33 | 31 | 20 | 20 |
| Dec | 30 | 29 | 17 | 17 |
Average hourly temperature in Den Chai
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 17°C.
Den Chai 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 | 30° / 16° | 18 | 2.1 | 11 | 6.2 |
| Feb | 33° / 18° | 10 | 1.3 | 11.4 | 4.7 |
| Mar | 35° / 21° | 31 | 4.1 | 11.9 | 2.9 |
| Apr | 36° / 24° | 62 | 9.1 | 12.4 | 2.0 |
| May | 34° / 25° | 205 | 20.6 | 12.8 | 2.3 |
| Jun | 32° / 25° | 236 | 25.1 | 13.1 | 2.4 |
| Jul | 31° / 25° | 274 | 27.1 | 13 | 2.5 |
| Aug | 31° / 24° | 341 | 28.9 | 12.6 | 2.5 |
| Sep | 31° / 24° | 295 | 26.6 | 12.1 | 2.6 |
| Oct | 31° / 23° | 126 | 15.8 | 11.6 | 3.9 |
| Nov | 31° / 20° | 30 | 4.6 | 11.2 | 5.4 |
| Dec | 29° / 17° | 14 | 2 | 10.9 | 6.6 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Den Chai gets about 1641 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 Apr 29 to Oct 18, peaking in August at about 93% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 7.
August is the wettest month by volume, with 341 mm over about 29 wet days; February is the driest, with 10 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 6 | 5 | 13 | 31 | 67 | 83 | 88 | 93 | 88 | 51 | 16 | 7 |
| Rain days | 2 | 1 | 4 | 9 | 21 | 25 | 27 | 29 | 27 | 16 | 5 | 2 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 6 | 2 |
| Feb | 5 | 1 |
| Mar | 13 | 4 |
| Apr | 31 | 9 |
| May | 67 | 21 |
| Jun | 83 | 25 |
| Jul | 88 | 27 |
| Aug | 93 | 29 |
| Sep | 88 | 27 |
| Oct | 51 | 16 |
| Nov | 16 | 5 |
| Dec | 7 | 2 |
Monthly rainfall
Over a full year, Den Chai collects about 1641 mm of rain across 167 wet days — roughly 137 mm in an average month.
It doesn’t fall evenly. August is the wettest month with 341 mm, while February is the driest at just 10 mm. The three wettest months alone bring about 55% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 18 | 10 | 31 | 62 | 205 | 236 | 274 | 341 | 295 | 126 | 30 | 14 |
| Rain days | 2 | 1 | 4 | 9 | 21 | 25 | 27 | 29 | 27 | 16 | 5 | 2 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 18 | 2 |
| Feb | 10 | 1 |
| Mar | 31 | 4 |
| Apr | 62 | 9 |
| May | 205 | 21 |
| Jun | 236 | 25 |
| Jul | 274 | 27 |
| Aug | 341 | 29 |
| Sep | 295 | 27 |
| Oct | 126 | 16 |
| Nov | 30 | 5 |
| Dec | 14 | 2 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Den Chai, 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 15 and lasts for 6.7 months, ending around May 5. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 89% of the time on average.
The cloudier part of the year begins around May 6 and lasts for 5.3 months, ending around October 14. The cloudiest month is August, when it is overcast or mostly cloudy 96% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 83 | 89 | 84 | 70 | 32 | 6 | 5 | 4 | 13 | 49 | 74 | 80 |
| Cloudier (%) | 17 | 11 | 16 | 30 | 68 | 94 | 95 | 96 | 87 | 51 | 26 | 20 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 83 | 17 |
| Feb | 89 | 11 |
| Mar | 84 | 16 |
| Apr | 70 | 30 |
| May | 32 | 68 |
| Jun | 6 | 94 |
| Jul | 5 | 95 |
| Aug | 4 | 96 |
| Sep | 13 | 87 |
| Oct | 49 | 51 |
| Nov | 74 | 26 |
| Dec | 80 | 20 |
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 June 10, brings about 13 h 06 min of light; the shortest, around January 1, only 10 h 54 min — a swing of roughly 2 h 12 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.0 | 11.4 | 11.9 | 12.4 | 12.8 | 13.1 | 13.0 | 12.6 | 12.1 | 11.6 | 11.2 | 10.9 |
| Sunrise (AM) | 6:58 | 6:53 | 6:33 | 6:08 | 5:51 | 5:48 | 5:56 | 6:06 | 6:11 | 6:17 | 6:31 | 6:48 |
| Sunset (PM) | 6:00 | 6:16 | 6:26 | 6:32 | 6:41 | 6:52 | 6:55 | 6:42 | 6:17 | 5:52 | 5:39 | 5:44 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 11.0 | 6:58 | 6:00 |
| Feb | 11.4 | 6:53 | 6:16 |
| Mar | 11.9 | 6:33 | 6:26 |
| Apr | 12.4 | 6:08 | 6:32 |
| May | 12.8 | 5:51 | 6:41 |
| Jun | 13.1 | 5:48 | 6:52 |
| Jul | 13.0 | 5:56 | 6:55 |
| Aug | 12.6 | 6:06 | 6:42 |
| Sep | 12.1 | 6:11 | 6:17 |
| Oct | 11.6 | 6:17 | 5:52 |
| Nov | 11.2 | 6:31 | 5:39 |
| Dec | 10.9 | 6:48 | 5:44 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Den Chai 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 24 days.
The sunnier stretch runs 6.3 months, from around Oct 22 to May 1. The sunniest month is February, with roughly 23 sunny days (brilliant).
The greyest month is August, down near 0 sunny days — about 100% fewer than the February peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 21 | 21 | 22 | 16 | 6 | 1 | 0 | 0 | 1 | 9 | 17 | 19 |
| Sky | Bright | Brilliant | Bright | Bright | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Bright | Bright |
| Sunny days | Sky | |
|---|---|---|
| Jan | 21 | Bright |
| Feb | 21 | Brilliant |
| Mar | 22 | Bright |
| Apr | 16 | Bright |
| May | 6 | Gloomy |
| Jun | 1 | Gloomy |
| Jul | 0 | Gloomy |
| Aug | 0 | Gloomy |
| Sep | 1 | Gloomy |
| Oct | 9 | Mixed |
| Nov | 17 | Bright |
| Dec | 19 | Bright |
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 Den Chai, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 8.3 months, from around March 18 to November 26. 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 27 to March 17, and December is the most comfortable month — the air is dry or comfortable 22% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 5 | 5 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 |
| Comfortable (%) | 18 | 17 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 18 |
| Humid (%) | 43 | 36 | 23 | 4 | 0 | 0 | 0 | 0 | 0 | 1 | 10 | 29 |
| Muggy (%) | 28 | 33 | 47 | 30 | 4 | 0 | 0 | 0 | 0 | 6 | 36 | 36 |
| Oppressive (%) | 6 | 9 | 23 | 59 | 45 | 21 | 18 | 12 | 9 | 41 | 39 | 12 |
| Miserable (%) | 0 | 0 | 0 | 7 | 51 | 79 | 82 | 88 | 90 | 52 | 11 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 5 | 18 | 43 | 28 | 6 | 0 |
| Feb | 5 | 17 | 36 | 33 | 9 | 0 |
| Mar | 1 | 7 | 23 | 47 | 23 | 0 |
| Apr | 0 | 0 | 4 | 30 | 59 | 7 |
| May | 0 | 0 | 0 | 4 | 45 | 51 |
| Jun | 0 | 0 | 0 | 0 | 21 | 79 |
| Jul | 0 | 0 | 0 | 0 | 18 | 82 |
| Aug | 0 | 0 | 0 | 0 | 12 | 88 |
| Sep | 0 | 0 | 0 | 0 | 9 | 90 |
| Oct | 0 | 0 | 1 | 6 | 41 | 52 |
| Nov | 0 | 3 | 10 | 36 | 39 | 11 |
| Dec | 5 | 18 | 29 | 36 | 12 | 1 |
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 Den Chai is typically calm, near 6 km/h, and varies little with the seasons.
The windier part of the year lasts 6.3 months, from around Feb 13 to Aug 23. The windiest month is June, averaging about 7 km/h (calm).
The calmer part of the year runs from around Aug 24 to Feb 12, with September the calmest month at about 4 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 5 | 6 | 7 | 6 | 6 | 7 | 7 | 6 | 4 | 4 | 4 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 5 | calm |
| Feb | 6 | calm |
| Mar | 7 | calm |
| Apr | 6 | calm |
| May | 6 | calm |
| Jun | 7 | calm |
| Jul | 7 | calm |
| Aug | 6 | calm |
| Sep | 4 | calm |
| Oct | 4 | calm |
| Nov | 4 | calm |
| Dec | 5 | calm |
Hazard calendar for Den Chai
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Den Chai's monsoon runs May–September, when most of the year's rain falls.
Best time to visit Den Chai
To characterize how pleasant the weather is in Den Chai throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late January, Den Chai is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
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 Den Chai for general outdoor tourist activities is from late November to early 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) | 6.2 | 4.7 | 3.0 | 2.1 | 2.3 | 2.4 | 2.5 | 2.5 | 2.6 | 3.9 | 5.4 | 6.6 |
| Rating | good | fair | poor | poor | poor | poor | poor | poor | poor | fair | fair | good |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 6.2 | good |
| Feb | 4.7 | fair |
| Mar | 3.0 | poor |
| Apr | 2.1 | poor |
| May | 2.3 | poor |
| Jun | 2.4 | poor |
| Jul | 2.5 | poor |
| Aug | 2.5 | poor |
| Sep | 2.6 | poor |
| Oct | 3.9 | fair |
| Nov | 5.4 | fair |
| Dec | 6.6 | good |
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 Den Chai 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 Den Chai, 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.
For a warm-season trip around April (highs near 36°C), the essentials are light clothes, rain gear and sun protection. In the cold season around December (highs near 29°C), pack light clothes.
In April, Den Chai sees daytime highs around 36°C and nights near 24°C. Pack light clothes and sun protection. Worth having: rain gear. About 9 days see rain.
UV index (midday) in Den Chai 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 Den Chai peaks around June 19 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (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) | 8 | 10 | 9 | 10 | 12 | 13 | 12 | 13 | 11 | 10 | 8 | 7 |
| Level | Very high | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 8 | Very high |
| Feb | 10 | Very high |
| Mar | 9 | Very high |
| Apr | 10 | Extreme |
| May | 12 | Extreme |
| Jun | 13 | Extreme |
| Jul | 12 | Extreme |
| Aug | 13 | Extreme |
| Sep | 11 | Extreme |
| Oct | 10 | Very high |
| Nov | 8 | Very high |
| Dec | 7 | Very high |
Average hourly UV index in Den Chai
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 June 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 6.5 | 7 | 7.5 | 7.5 | 8.5 | 8.5 | 8.5 | 8 | 7.5 | 7 | 6.5 | 6 |
| UV ≥ 6 (h/day) | 4 | 4.5 | 5 | 5.5 | 6 | 6.5 | 6.5 | 6.5 | 5.5 | 5 | 3.5 | 3 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 6.5 | 4 |
| Feb | 7 | 4.5 |
| Mar | 7.5 | 5 |
| Apr | 7.5 | 5.5 |
| May | 8.5 | 6 |
| Jun | 8.5 | 6.5 |
| Jul | 8.5 | 6.5 |
| Aug | 8 | 6.5 |
| Sep | 7.5 | 5.5 |
| Oct | 7 | 5 |
| Nov | 6.5 | 3.5 |
| Dec | 6 | 3 |
Air quality in Den Chai 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 Den Chai is worst in March — around 63 µg/m³ PM2.5 (unhealthy), about 3.1× the cleanest month (June, 21 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) | 43 | 49 | 63 | 53 | 31 | 21 | 21 | 22 | 26 | 31 | 33 | 36 |
| Level | Poor | Poor | Unhealthy | Poor | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 43 | Poor |
| Feb | 49 | Poor |
| Mar | 63 | Unhealthy |
| Apr | 53 | Poor |
| May | 31 | Moderate |
| Jun | 21 | Moderate |
| Jul | 21 | Moderate |
| Aug | 22 | Moderate |
| Sep | 26 | Moderate |
| Oct | 31 | Moderate |
| Nov | 33 | Moderate |
| Dec | 36 | Poor |
Growing season
Den Chai 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. Den Chai banks about 6,182 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) | 409 | 428 | 563 | 604 | 599 | 554 | 551 | 541 | 527 | 529 | 466 | 411 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 409 |
| Feb | 428 |
| Mar | 563 |
| Apr | 604 |
| May | 599 |
| Jun | 554 |
| Jul | 551 |
| Aug | 541 |
| Sep | 527 |
| Oct | 529 |
| Nov | 466 |
| Dec | 411 |
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.
Den Chai receives about 4.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.8 and 6.3 kWh/m².
The brighter stretch of the year lasts 4.3 months, from around Jan 22 to May 31. The brightest month is April, averaging about 6.2 kWh/m² (intense).
The dimmest month is August, down near 3.9 kWh/m² — roughly 37% less than the April peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.7 | 5.5 | 6.1 | 6.2 | 5.3 | 4.5 | 4.1 | 3.9 | 4.2 | 4.5 | 4.5 | 4.4 |
| Level | Bright | Bright | Intense | Intense | Bright | Bright | Bright | Moderate | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 4.7 | Bright |
| Feb | 5.5 | Bright |
| Mar | 6.1 | Intense |
| Apr | 6.2 | Intense |
| May | 5.3 | Bright |
| Jun | 4.5 | Bright |
| Jul | 4.1 | Bright |
| Aug | 3.9 | Moderate |
| Sep | 4.2 | Bright |
| Oct | 4.5 | Bright |
| Nov | 4.5 | Bright |
| Dec | 4.4 | Bright |
Where is Den Chai?
Den Chai sits at 18.0°N, 100.1°E, 159 m above sea level, in Thailand. The nearest listed city is Phrae, 20 km away.
Topography around Den Chai
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Den Chai.
Within 3 km, the terrain around Den Chai has only modest variations in elevation — a maximum elevation change of 159 m around an average of 166 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,034 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,610 m.
The land around Den Chai is covered by trees (46%) and cropland (40%) within 3 km, trees (81%) within 16 km, and trees (76%) 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 Den Chai (17.9837°, 100.0522°, elevation 159 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).