Climate and average weather in Boyolali
In Boyolali, the weather is muggy, hot, wet, and mostly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around February.
Over the course of the year, the temperature in Boyolali typically varies from 19°C to 29°C, and is rarely below 17°C or above 31°C. April is the hottest month of the year, while July is the coldest.
Based on the travel score, the best time of year to visit Boyolali for warm-weather activities is from late June to late September.
- Hottest
- Apr
- 29°
- Coldest
- Jul
- 19°
- Wettest
- Feb
- 451 mm
- Driest
- Aug
- 42 mm
- Rain / yr
- 2913 mm
- 249 wet days
- Daylight
- 11.6–12.4 h
- shortest–longest
- Elevation
- 438 m
- 7.5°S
- Clearest
- Aug
- 61% cloud
Boyolali 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 June to late September.
Temperature through the year
Daily average highs and lows in Boyolali, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in Boyolali stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 29°C and low of 21°C; the coolest is July, with an average low of 19°C and high of 28°C.
Days typically run about 8°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 28 | 29 | 29 | 29 | 28 | 28 | 28 | 28 | 29 | 29 | 28 |
| Avg low (°C) | 21 | 21 | 21 | 21 | 21 | 20 | 19 | 19 | 20 | 21 | 21 | 21 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 28 | 21 |
| Feb | 28 | 21 |
| Mar | 29 | 21 |
| Apr | 29 | 21 |
| May | 29 | 21 |
| Jun | 28 | 20 |
| Jul | 28 | 19 |
| Aug | 28 | 19 |
| Sep | 28 | 20 |
| Oct | 29 | 21 |
| Nov | 29 | 21 |
| Dec | 28 | 21 |
Average hourly temperature in Boyolali
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 29°C, and coldest before dawn in July, near 19°C.
Boyolali 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 | 28° / 21° | 447 | 29.2 | 12.4 | 3.2 |
| Feb | 28° / 21° | 451 | 27.4 | 12.2 | 3.0 |
| Mar | 29° / 21° | 407 | 29.3 | 12.1 | 3.0 |
| Apr | 29° / 21° | 282 | 26.7 | 11.8 | 3.3 |
| May | 29° / 21° | 148 | 20.4 | 11.7 | 4.3 |
| Jun | 28° / 20° | 96 | 14.7 | 11.6 | 5.3 |
| Jul | 28° / 19° | 62 | 10.4 | 11.6 | 6.3 |
| Aug | 28° / 19° | 42 | 6.8 | 11.8 | 6.8 |
| Sep | 28° / 20° | 71 | 9.6 | 12 | 5.7 |
| Oct | 29° / 21° | 179 | 19.7 | 12.2 | 4.3 |
| Nov | 29° / 21° | 340 | 26.9 | 12.3 | 3.3 |
| Dec | 28° / 21° | 387 | 27.9 | 12.4 | 3.3 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Boyolali gets about 2913 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 6.7 months, from around Oct 21 to May 11, peaking in February at about 98% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 8.
February is the wettest month by volume, with 451 mm over about 27 wet days; August is the driest, with 42 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 94 | 98 | 95 | 88 | 66 | 49 | 33 | 23 | 33 | 63 | 89 | 90 |
| Rain days | 29 | 27 | 29 | 27 | 20 | 15 | 10 | 7 | 10 | 20 | 27 | 28 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 94 | 29 |
| Feb | 98 | 27 |
| Mar | 95 | 29 |
| Apr | 88 | 27 |
| May | 66 | 20 |
| Jun | 49 | 15 |
| Jul | 33 | 10 |
| Aug | 23 | 7 |
| Sep | 33 | 10 |
| Oct | 63 | 20 |
| Nov | 89 | 27 |
| Dec | 90 | 28 |
Monthly rainfall
Over a full year, Boyolali collects about 2913 mm of rain across 249 wet days — roughly 243 mm in an average month.
It doesn’t fall evenly. February is the wettest month with 451 mm, while August is the driest at just 42 mm. The three wettest months alone bring about 45% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 447 | 451 | 407 | 282 | 148 | 96 | 62 | 42 | 71 | 179 | 340 | 387 |
| Rain days | 29 | 27 | 29 | 27 | 20 | 15 | 10 | 7 | 10 | 20 | 27 | 28 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 447 | 29 |
| Feb | 451 | 27 |
| Mar | 407 | 29 |
| Apr | 282 | 27 |
| May | 148 | 20 |
| Jun | 96 | 15 |
| Jul | 62 | 10 |
| Aug | 42 | 7 |
| Sep | 71 | 10 |
| Oct | 179 | 20 |
| Nov | 340 | 27 |
| Dec | 387 | 28 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Boyolali, 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 April 30 and lasts for 5.8 months, ending around October 22. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 48% of the time on average.
The cloudier part of the year begins around October 23 and lasts for 6.2 months, ending around April 29. The cloudiest month is February, when it is overcast or mostly cloudy 98% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 4 | 2 | 6 | 14 | 33 | 42 | 45 | 48 | 40 | 26 | 9 | 4 |
| Cloudier (%) | 96 | 98 | 94 | 86 | 67 | 58 | 55 | 52 | 60 | 74 | 91 | 96 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 4 | 96 |
| Feb | 2 | 98 |
| Mar | 6 | 94 |
| Apr | 14 | 86 |
| May | 33 | 67 |
| Jun | 42 | 58 |
| Jul | 45 | 55 |
| Aug | 48 | 52 |
| Sep | 40 | 60 |
| Oct | 26 | 74 |
| Nov | 9 | 91 |
| Dec | 4 | 96 |
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 January 1, brings about 12 h 24 min of light; the shortest, around May 18, only 11 h 36 min — a swing of roughly 0 h 48 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.4 | 12.2 | 12.1 | 11.8 | 11.7 | 11.6 | 11.6 | 11.8 | 12.0 | 12.2 | 12.3 | 12.4 |
| Sunrise (AM) | 5:35 | 5:45 | 5:46 | 5:43 | 5:44 | 5:51 | 5:55 | 5:49 | 5:33 | 5:18 | 5:12 | 5:21 |
| Sunset (PM) | 5:59 | 6:00 | 5:49 | 5:33 | 5:24 | 5:25 | 5:31 | 5:34 | 5:31 | 5:28 | 5:33 | 5:47 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 12.4 | 5:35 | 5:59 |
| Feb | 12.2 | 5:45 | 6:00 |
| Mar | 12.1 | 5:46 | 5:49 |
| Apr | 11.8 | 5:43 | 5:33 |
| May | 11.7 | 5:44 | 5:24 |
| Jun | 11.6 | 5:51 | 5:25 |
| Jul | 11.6 | 5:55 | 5:31 |
| Aug | 11.8 | 5:49 | 5:34 |
| Sep | 12.0 | 5:33 | 5:31 |
| Oct | 12.2 | 5:18 | 5:28 |
| Nov | 12.3 | 5:12 | 5:33 |
| Dec | 12.4 | 5:21 | 5:47 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Boyolali averages about 2 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 7 days.
The sunnier stretch runs 5.6 months, from around May 2 to Oct 17. The sunniest month is June, with roughly 6 sunny days (gloomy).
The greyest month is January, down near 0 sunny days — about 98% fewer than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 0 | 0 | 0 | 1 | 4 | 5 | 5 | 6 | 4 | 2 | 1 | 0 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 0 | Gloomy |
| Feb | 0 | Gloomy |
| Mar | 0 | Gloomy |
| Apr | 1 | Gloomy |
| May | 4 | Gloomy |
| Jun | 5 | Gloomy |
| Jul | 5 | Gloomy |
| Aug | 6 | Gloomy |
| Sep | 4 | Gloomy |
| Oct | 2 | Gloomy |
| Nov | 1 | Gloomy |
| Dec | 0 | Gloomy |
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.
Boyolali is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.
The stickiest month is January, when it feels muggy, oppressive or miserable about 100% of the time. Even in September, the mildest month, the air is dry or comfortable only 1% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Comfortable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 |
| Humid (%) | 0 | 0 | 0 | 0 | 2 | 8 | 24 | 31 | 18 | 5 | 0 | 0 |
| Muggy (%) | 29 | 23 | 20 | 14 | 31 | 53 | 59 | 60 | 70 | 57 | 25 | 29 |
| Oppressive (%) | 71 | 77 | 80 | 86 | 67 | 40 | 16 | 7 | 11 | 38 | 75 | 71 |
| Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|
| Jan | 0 | 0 | 29 | 71 |
| Feb | 0 | 0 | 23 | 77 |
| Mar | 0 | 0 | 20 | 80 |
| Apr | 0 | 0 | 14 | 86 |
| May | 0 | 2 | 31 | 67 |
| Jun | 0 | 8 | 53 | 40 |
| Jul | 0 | 24 | 59 | 16 |
| Aug | 1 | 31 | 60 | 7 |
| Sep | 1 | 18 | 70 | 11 |
| Oct | 0 | 5 | 57 | 38 |
| Nov | 0 | 0 | 25 | 75 |
| Dec | 0 | 0 | 29 | 71 |
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 Boyolali is steady company: average speeds sit near 5 km/h — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 4 | 4 | 4 | 4 | 4 | 5 | 5 | 6 | 6 | 6 | 5 | 4 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 4 | calm |
| Feb | 4 | calm |
| Mar | 4 | calm |
| Apr | 4 | calm |
| May | 4 | calm |
| Jun | 5 | calm |
| Jul | 5 | calm |
| Aug | 6 | calm |
| Sep | 6 | calm |
| Oct | 6 | calm |
| Nov | 5 | calm |
| Dec | 4 | calm |
Hazard calendar for Boyolali
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Boyolali sits in the South Indian Ocean cyclone belt; the season peaks January–March.
Boyolali's rainy season runs November–April, when most of the year's rain falls.
Best time to visit Boyolali
To characterize how pleasant the weather is in Boyolali throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around mid September, Boyolali 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 Boyolali for general outdoor tourist activities is from late June to late September, with a peak score in the second week of August.
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) | 3.2 | 3.0 | 3.0 | 3.3 | 4.3 | 5.3 | 6.3 | 6.7 | 5.7 | 4.3 | 3.3 | 3.2 |
| Rating | poor | poor | poor | poor | fair | fair | good | good | good | fair | poor | poor |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 3.2 | poor |
| Feb | 3.0 | poor |
| Mar | 3.0 | poor |
| Apr | 3.3 | poor |
| May | 4.3 | fair |
| Jun | 5.3 | fair |
| Jul | 6.3 | good |
| Aug | 6.7 | good |
| Sep | 5.7 | good |
| Oct | 4.3 | fair |
| Nov | 3.3 | poor |
| Dec | 3.2 | poor |
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 Boyolali for hot-weather activities is from mid June to early October, with a peak score in the second week of August.
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 Boyolali, 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.
Boyolali packs about the same all year — highs hold near 29°C. Across the year the things worth having are light clothes, rain gear and sun protection.
In April, Boyolali sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.
Sea temperature near Boyolali
Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.
The sea at the nearest coast (about 64 km away) is warmest in March at about 29°C and coldest in August near 25°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 29 | 29 | 29 | 29 | 29 | 28 | 26 | 25 | 25 | 26 | 28 | 29 |
| Comfort | Tropical | Tropical | Tropical | Tropical | Tropical | Warm | Warm | Warm | Warm | Warm | Warm | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 29 | Tropical |
| Feb | 29 | Tropical |
| Mar | 29 | Tropical |
| Apr | 29 | Tropical |
| May | 29 | Tropical |
| Jun | 28 | Warm |
| Jul | 26 | Warm |
| Aug | 25 | Warm |
| Sep | 25 | Warm |
| Oct | 26 | Warm |
| Nov | 28 | Warm |
| Dec | 29 | Tropical |
UV index (midday) in Boyolali 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 Boyolali peaks around March 14 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 14 at about 6 (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) | 14 | 14 | 15 | 12 | 8 | 6 | 10 | 11 | 13 | 13 | 9 | 11 |
| Level | Extreme | Extreme | Extreme | Extreme | Very high | High | Very high | Extreme | Extreme | Extreme | Very high | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 14 | Extreme |
| Feb | 14 | Extreme |
| Mar | 15 | Extreme |
| Apr | 12 | Extreme |
| May | 8 | Very high |
| Jun | 6 | High |
| Jul | 10 | Very high |
| Aug | 11 | Extreme |
| Sep | 13 | Extreme |
| Oct | 13 | Extreme |
| Nov | 9 | Very high |
| Dec | 11 | Extreme |
Average hourly UV index in Boyolali
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 March 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) | 8.5 | 8 | 8.5 | 7.5 | 7 | 6 | 7 | 7.5 | 8 | 8 | 7.5 | 8 |
| UV ≥ 6 (h/day) | 6.5 | 6.5 | 6.5 | 5.5 | 4 | 1.5 | 5 | 5.5 | 6 | 6 | 5 | 5.5 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 8.5 | 6.5 |
| Feb | 8 | 6.5 |
| Mar | 8.5 | 6.5 |
| Apr | 7.5 | 5.5 |
| May | 7 | 4 |
| Jun | 6 | 1.5 |
| Jul | 7 | 5 |
| Aug | 7.5 | 5.5 |
| Sep | 8 | 6 |
| Oct | 8 | 6 |
| Nov | 7.5 | 5 |
| Dec | 8 | 5.5 |
Air quality in Boyolali 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 Boyolali is worst in April — around 58 µg/m³ PM2.5 (unhealthy), about 1.7× the cleanest month (September, 34 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) | 48 | 46 | 54 | 58 | 57 | 51 | 42 | 35 | 34 | 37 | 42 | 42 |
| Level | Poor | Poor | Poor | Unhealthy | Unhealthy | Poor | Poor | Moderate | Moderate | Poor | Poor | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 48 | Poor |
| Feb | 46 | Poor |
| Mar | 54 | Poor |
| Apr | 58 | Unhealthy |
| May | 57 | Unhealthy |
| Jun | 51 | Poor |
| Jul | 42 | Poor |
| Aug | 35 | Moderate |
| Sep | 34 | Moderate |
| Oct | 37 | Poor |
| Nov | 42 | Poor |
| Dec | 42 | Poor |
Growing season
Boyolali 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. Boyolali banks about 5,234 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) | 447 | 407 | 458 | 449 | 459 | 425 | 416 | 412 | 417 | 451 | 442 | 451 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 447 |
| Feb | 407 |
| Mar | 458 |
| Apr | 449 |
| May | 459 |
| Jun | 425 |
| Jul | 416 |
| Aug | 412 |
| Sep | 417 |
| Oct | 451 |
| Nov | 442 |
| Dec | 451 |
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.
Boyolali receives about 5.0 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.4 and 5.9 kWh/m².
The brighter stretch of the year lasts 3.9 months, from around Jul 21 to Nov 15. The brightest month is September, averaging about 5.8 kWh/m² (bright).
The dimmest month is January, down near 4.5 kWh/m² — roughly 23% less than the September peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.5 | 4.5 | 4.8 | 4.8 | 4.9 | 4.7 | 4.9 | 5.4 | 5.9 | 5.8 | 5.0 | 4.5 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 4.5 | Bright |
| Feb | 4.5 | Bright |
| Mar | 4.8 | Bright |
| Apr | 4.8 | Bright |
| May | 4.9 | Bright |
| Jun | 4.7 | Bright |
| Jul | 4.9 | Bright |
| Aug | 5.4 | Bright |
| Sep | 5.9 | Bright |
| Oct | 5.8 | Bright |
| Nov | 5.0 | Bright |
| Dec | 4.5 | Bright |
Where is Boyolali?
Boyolali sits at 7.5°S, 110.6°E, 438 m above sea level, in Indonesia. The nearest listed city is Karanganom, 13 km away.
Topography around Boyolali
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Boyolali.
Within 3 km, the terrain around Boyolali has significant variations in elevation — a maximum elevation change of 260 m around an average of 440 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 2,558 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,291 m.
The land around Boyolali is covered by trees (64%) and artificial surfaces (31%) within 3 km, trees (67%) within 16 km, and trees (61%) and cropland (21%) within 80 km.
Indonesia travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F
- 230 V · 50 Hz
- Prices
- ≈ 29% of US
- price level, 2025
- GDP per capita
- $5,060
- 2025
- Happiness
- 5.6 / 10
- World Happiness, 2025
- Safe drinking water
- 30%
- of population, 2024
- Homicide rate
- 0.3
- per 100k, 2022
- Road deaths
- 11.3
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Low
- EF EPI 471
- 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 Boyolali (-7.5331°, 110.5958°, elevation 438 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). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).