Cilegon weather in May

In May, Cilegon sees average daytime highs of 30°C and overnight lows near 26°C, with 165 mm of rain across 23.8 wet days and about 11.7 hours of daylight. It is the 1st-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 16% of the time in May, and the air most often feels miserable.

Daylight stretches from about 11 h 48 min at the start of May to 11 h 42 min by month's end. Set against the rest of the year, May is Cilegon's 5th-clearest and 8th-windiest month. For the whole year in context, see Cilegon's year-round climate.

Daytime high
30°
1st warmest
Overnight low
26°
12th coldest
Rainfall
165 mm
23.8 wet days
Daylight
11 h 42 min
6:00 AM – 5:44 PM
Cloud cover
69%
5th clearest
Wind
6 km/h
8th windiest
Solar energy
5 kWh/m²
Travel score
3.4
out of 10

Cilegon is city in Banten Province, Indonesia.

Density
2,680/km²
people per km²
Founded
1999

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical May day in Cilegon reaches about 30°C in the afternoon and slips back to 26°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 31°C. Set against its neighbours, May runs on par with April and on par with June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13026
23026
33026
43026
53026
63026
73026
83026
93026
103026
113026
123026
133026
143026
153026
163026
173026
183026
193026
203026
213026
223026
233026
243026
253026
263026
273026
283026
293025
303025
313025

How May really feels in Cilegon

Once humidity and wind are folded in, May averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Cilegon weather by month

How May compares with the rest of the year at a glance. May is the 1st-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 25°28528.612.33.1
Feb29° / 25°26126.112.23.0
Mar29° / 25°25128123.0
Apr30° / 26°21826.511.93.0
May30° / 26°16523.811.73.4
Jun30° / 25°12020.111.73.9
Jul29° / 25°9418.111.74.4
Aug29° / 24°701711.84.5
Sep30° / 25°7415.9124.3
Oct30° / 25°13420.312.13.7
Nov30° / 25°22325.212.33.2
Dec29° / 25°29327.112.33.2

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 21% of May, with mostly cloudy or overcast conditions the remaining 64%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12476
22476
32575
42575
52674
62674
72773
82872
92971
103070
113169
123367
133565
143763
153763
163961
174060
184159
194258
204456
214456
224456
234555
244555
254555
264555
274555
284555
294555
304357
314357

Chance of precipitation in May

Any precipitation

Cilegon gets around 165 mm of rain over 23.8 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 77% and peaks near 85% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
185
285
385
485
584
684
784
883
982
1081
1181
1280
1379
1478
1577
1676
1775
1874
1973
2073
2172
2272
2371
2471
2571
2671
2771
2871
2971
3071
3172

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the miserable band about 79% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
101387
201387
301387
401387
501486
601486
701585
801585
901684
1001684
1101783
1201882
1301981
1401981
1502080
1602179
1702278
1802278
1902377
2002476
2102575
2202575
2302674
2402773
2502773
2612871
2712871
2812871
2912871
3012871
3112970

Wind in May

Winds average 6 km/h in May.

Across May, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
317calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 h 48 min at the start of May to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over May. Sunrise moves from 5:59 AM to 6:03 AM, and sunset from 5:47 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.85:595:47
211.85:595:46
311.85:595:46
411.85:595:46
511.85:595:46
611.85:595:45
711.85:595:45
811.85:595:45
911.86:005:45
1011.86:005:45
1111.76:005:45
1211.76:005:44
1311.76:005:44
1411.76:005:44
1511.76:005:44
1611.76:005:44
1711.76:005:44
1811.76:005:44
1911.76:015:44
2011.76:015:44
2111.76:015:43
2211.76:015:43
2311.76:015:43
2411.76:015:43
2511.76:025:43
2611.76:025:43
2711.76:025:43
2811.76:025:43
2911.76:025:43
3011.76:035:44
3111.76:035:44

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5 kWh/m².

For context, solar energy here swings from a low near 4.69 kWh/m² to a high of 6.03 kWh/m² in September across the year — May's 5 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
295.0Bright
304.9Bright
314.9Bright
Planning a trip in May

Hazard calendar for Cilegon

In seasonPeak

None of Cilegon's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

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

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

Is May a good time to visit Cilegon?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.4
Sightseeing
6th-best month of the year
4.6
Beach & pool
6th-best month of the year

May is a weaker month for outdoor sightseeing in Cilegon.

What to pack for Cilegon in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Cilegon sees daytime highs around 30°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

Sea temperature near Cilegon in May

The nearest coast averages about 30°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 17 km away) is warmest in May at about 30°C and coldest in January near 29°C.

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

28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr30Tropical
May30Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov30Tropical
Dec29Tropical

UV index in Cilegon in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cilegon peaks around March 14 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 16 at about 7 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeVery highMar 14UV 15Nov 16UV 7
UV index (midday)Level
Jan13Extreme
Feb13Extreme
Mar15Extreme
Apr11Extreme
May9Very high
Jun8Very high
Jul9Very high
Aug10Very high
Sep9Very high
Oct11Extreme
Nov6High
Dec12Extreme

Air quality in Cilegon in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Cilegon is worst in August — around 37 µg/m³ PM2.5 (poor), about 2.7× the cleanest month (December, 14 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateModeratePoorModerateAug 2037 µg/m³Dec 2114 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb18Moderate
Mar17Moderate
Apr24Moderate
May36Poor
Jun33Moderate
Jul35Poor
Aug37Poor
Sep36Poor
Oct33Moderate
Nov22Moderate
Dec14Moderate
Location & terrain

Where is Cilegon?

Cilegon sits at 6.0°S, 106.1°E, 18 m above sea level, in Indonesia. The nearest listed city is Serang, 16 km away.

Topography around Cilegon

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

Within 3 km, the terrain around Cilegon has only modest variations in elevation — a maximum elevation change of 67 m around an average of 17 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 634 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,756 m.

The land around Cilegon is covered by artificial surfaces (48%) and trees (26%) within 3 km, trees (40%) and water (31%) within 16 km, and water (56%) and trees (30%) within 80 km.

3 km
67 m
16 km
634 m
80 km
1,756 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Serang 16 km · Pandeglang 33 km · Kresek 38 km · Rangkasbitung 44 km · Labuan 47 km · Pasarkemis 55 km · Cikupa 56 km · Sepatan 59 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 Cilegon (-6.0144°, 106.0542°, elevation 18 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).