Climate and average weather in Cilacap

In Cilacap, 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 December.

Best: late June to early October

Over the course of the year, the temperature in Cilacap typically varies from 24°C to 28°C, and is rarely below 23°C or above 29°C. April is the hottest month of the year, while August is the coldest.

Based on the travel score, the best time of year to visit Cilacap for warm-weather activities is from late June to early October.

Hottest
Apr
28°
Coldest
Aug
24°
Wettest
Dec
394 mm
Driest
Aug
72 mm
Rain / yr
2573 mm
284 wet days
Daylight
11.6–12.4 h
shortest–longest
Elevation
10 m
7.7°S
Clearest
Aug
53% cloud

Cilacap is capital of Cilacap Regency.

Founded
1982

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Cilacap 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 early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Cilacap stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 28°C and low of 26°C; the coolest is August, with an average low of 24°C and high of 26°C.

Days typically run about 2°C warmer than nights year-round.

18°20°22°24°26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2826
Feb2826
Mar2826
Apr2826
May2826
Jun2825
Jul2725
Aug2624
Sep2624
Oct2725
Nov2725
Dec2826

How hot and cold Cilacap 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, Cilacap feels like about 33°C (around April 30). About 58 days a year carry some heat stress, peaking in April.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan31282626
Feb31282626
Mar32282626
Apr32282626
May32282626
Jun31282525
Jul27272425
Aug26262424
Sep26262424
Oct27272525
Nov30272525
Dec31282626

Average hourly temperature in Cilacap

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 28°C, and coldest before dawn in August, near 24°C.

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

Cilacap 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
Jan28° / 26°31628.212.43.6
Feb28° / 26°2402512.33.6
Mar28° / 26°25927.912.13.4
Apr28° / 26°2062711.83.4
May28° / 26°1622511.74.0
Jun28° / 25°12721.411.64.8
Jul27° / 25°10117.711.65.5
Aug26° / 24°7215.311.76.0
Sep26° / 24°11017.9125.4
Oct27° / 25°22123.412.24.6
Nov27° / 25°36527.512.43.6
Dec28° / 26°39428.112.43.5

Chance of rain

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

Cilacap gets about 2573 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 7.0 months, from around Oct 20 to May 19, peaking in December at about 93% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 15.

December is the wettest month by volume, with 394 mm over about 28 wet days; August is the driest, with 72 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetDec 6 · 93%Aug 15 · 49%
Rain on a day (%)Rain days
Jan9128
Feb8925
Mar9028
Apr9027
May8025
Jun7121
Jul5718
Aug5015
Sep6018
Oct7523
Nov9128
Dec9128

Monthly rainfall

Over a full year, Cilacap collects about 2573 mm of rain across 284 wet days — roughly 214 mm in an average month.

It doesn’t fall evenly. December is the wettest month with 394 mm, while August is the driest at just 72 mm. The three wettest months alone bring about 42% of the year’s total.

050100150200250300350400450JanFebMarAprMayJunJulAugSepOctNovDec31624025920616212710172110221365394
Rainfall (mm)Rain days
Jan31628
Feb24025
Mar25928
Apr20627
May16225
Jun12721
Jul10118
Aug7215
Sep11018
Oct22123
Nov36528
Dec39428

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Cilacap, 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 28 and lasts for 5.9 months, ending around October 23. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 61% of the time on average.

The cloudier part of the year begins around October 24 and lasts for 6.1 months, ending around April 27. The cloudiest month is February, when it is overcast or mostly cloudy 90% 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%JanFebMarAprMayJunJulAugSepOctNovDecAug 11 · 64%Dec 9 · 8%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1387
Feb1090
Mar1684
Apr2575
May4654
Jun5446
Jul5743
Aug6139
Sep5347
Oct3862
Nov1684
Dec1090

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 January 1, brings about 12 h 24 min of light; the shortest, around May 16, only 11 h 36 min — a swing of roughly 0 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.45:416:05
Feb12.35:516:06
Mar12.15:525:55
Apr11.85:495:39
May11.75:515:30
Jun11.65:585:31
Jul11.66:025:37
Aug11.75:565:40
Sep12.05:405:37
Oct12.25:245:34
Nov12.45:185:40
Dec12.45:275:54

Sunny days

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

Cilacap averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 11 days.

The sunnier stretch runs 5.9 months, from around Apr 29 to Oct 25. The sunniest month is August, with roughly 10 sunny days (mixed).

The greyest month is February, down near 1 sunny days — about 95% fewer than the August peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedAug 1011 daysFeb 60 days
Sunny daysSky
Jan1Gloomy
Feb1Gloomy
Mar2Gloomy
Apr4Gloomy
May9Mixed
Jun10Mixed
Jul11Mixed
Aug10Mixed
Sep9Mixed
Oct6Gloomy
Nov2Gloomy
Dec1Gloomy

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.

Cilacap 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 January, the mildest month, the air is dry or comfortable only 0% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggy
Muggy (%)Oppressive (%)Miserable (%)
Jan08317
Feb08020
Mar07327
Apr05743
May15346
Jun37422
Jul16804
Aug23751
Sep11881
Oct2945
Nov08812
Dec18415

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 Cilacap is typically light breeze, near 12 km/h, and varies moderately with the seasons.

The windier part of the year lasts 4.7 months, from around May 29 to Oct 19. The windiest month is August, averaging about 18 km/h (light breeze).

The calmer part of the year runs from around Oct 20 to May 28, with April the calmest month at about 9 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezebreezyAug 11 · 18 km/hApr 6 · 8 km/h
Wind speed (km/h)Feels
Jan11calm
Feb11calm
Mar9calm
Apr9calm
May11calm
Jun14light breeze
Jul16light breeze
Aug18light breeze
Sep16light breeze
Oct13light breeze
Nov10calm
Dec11calm

Hazard calendar for Cilacap

In seasonPeak

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

Cilacap sits in the South Indian Ocean cyclone belt; the season peaks January–March.

Cilacap's rainy season runs October–April, when most of the year's rain falls.

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

Best time to visit Cilacap

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late September, Cilacap 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 Cilacap for general outdoor tourist activities is from late June to mid October, with a peak score in the second week of August.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationAug 13 · 6.0

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
Jan3.6fair
Feb3.6fair
Mar3.4poor
Apr3.4poor
May4.0fair
Jun4.8fair
Jul5.5good
Aug5.9good
Sep5.4fair
Oct4.6fair
Nov3.6fair
Dec3.5fair

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 Cilacap for hot-weather activities is from mid May to mid October, with a peak score in the second week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 13 · 5.8

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 Cilacap, 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.

Cilacap packs about the same all year — highs hold near 28°C. Across the year the things worth having are light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In April, Cilacap sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

Sea temperature near Cilacap

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 21 km away) is warmest in April at about 29°C and coldest in August near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun28Warm
Jul27Warm
Aug26Warm
Sep26Warm
Oct27Warm
Nov28Warm
Dec29Tropical

UV index (midday) in Cilacap 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 Cilacap peaks around March 12 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 14 at about 7 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeExtremeMar 12UV 15Jun 14UV 7
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar15Extreme
Apr12Extreme
May9Very high
Jun7High
Jul10Very high
Aug11Extreme
Sep12Extreme
Oct13Extreme
Nov9Very high
Dec12Extreme

Average hourly UV index in Cilacap

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 March 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.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan8.56.5
Feb8.56.5
Mar86.5
Apr86
May74.5
Jun6.53.5
Jul75
Aug7.55.5
Sep86
Oct86
Nov7.55
Dec86

Air quality in Cilacap 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 Cilacap is worst in May — around 46 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModerateMay 1545 µg/m³Sep 1630 µg/m³
PM2.5 (µg/m³)Level
Jan39Poor
Feb39Poor
Mar41Poor
Apr44Poor
May46Poor
Jun43Poor
Jul37Poor
Aug31Moderate
Sep30Moderate
Oct31Moderate
Nov32Moderate
Dec33Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Cilacap 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. Cilacap banks about 5,957 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around April.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan523
Feb475
Mar528
Apr513
May527
Jun493
Jul481
Aug466
Sep454
Oct487
Nov490
Dec518

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.

Cilacap receives about 5.0 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.6 and 5.6 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseSep 225.6 kWhJun 134.6 kWh
Solar energy (kWh/m²)Level
Jan4.9Bright
Feb5.0Bright
Mar5.1Bright
Apr5.0Bright
May4.8Bright
Jun4.6Bright
Jul4.7Bright
Aug5.3Bright
Sep5.6Bright
Oct5.5Bright
Nov4.9Bright
Dec4.7Bright

Where is Cilacap?

Cilacap sits at 7.7°S, 109.0°E, 10 m above sea level, in Indonesia. The nearest listed city is Wangon, 24 km away.

Topography around Cilacap

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

Within 3 km, the terrain around Cilacap has only modest variations in elevation — a maximum elevation change of 123 m around an average of 6 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 209 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,396 m.

The land around Cilacap is covered by artificial surfaces (42%) and water (36%) within 3 km, water (51%) and trees (24%) within 16 km, and trees (49%) and water (35%) within 80 km.

3 km
123 m
16 km
209 m
80 km
3,396 m
treesgrasslandcroplandartificial surfaceswatermangroves
Nearby: Wangon 24 km · Kroya 28 km · Sidareja 36 km · Banyumas 39 km · Purwokerto 42 km · Sokaraja 43 km · Baturaden 53 km · Purbalingga 54 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
Muslim 87%Protestant 8%Roman Catholic 3%Hindu 2%

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 Cilacap (-7.7264°, 109.0094°, elevation 10 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).