Cilegon in Spring
In spring (September, October and November), Cilegon sees average daytime highs around 30°C and overnight lows near 25°C, with 431 mm of rain over about 61 wet days across the season. It is the warmest season of the year and the 3rd-wettest season.
Across spring, daytime highs hold fairly steady around 30°C. The sky is clear or mostly clear about 12% of the time across spring, and the air most often feels oppressive.
Spring is Cilegon's 2nd-best season to visit on our travel score. Cilegon has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see Cilegon's year-round climate.
- Avg daytime high
- 30°C
- warmest season of the year
- Avg overnight low
- 25°C
- Rainfall
- 431 mm
- 61 wet days
- Avg wind
- 7 km/h
- Travel score
- 3.7
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Cilegon in Spring
Across spring, daytime highs hold fairly steady around 30°C.
A typical spring day in Cilegon reaches about 30°C and drops to 25°C overnight. The warmest of the three months is October, the coolest September.
How spring really feels in Cilegon
Once humidity and wind are folded in, spring brings about 91 days that feel above 32°C and 0 that feel at or below 0°C.
The story in spring is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Cilegon weather by month
How the three spring months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 29° / 25° | 285 | 28.6 | 12.3 | 3.1 |
| Feb | 29° / 25° | 261 | 26.1 | 12.2 | 3.0 |
| Mar | 29° / 25° | 251 | 28 | 12 | 3.0 |
| Apr | 30° / 26° | 218 | 26.5 | 11.9 | 3.0 |
| May | 30° / 26° | 165 | 23.8 | 11.7 | 3.4 |
| Jun | 30° / 25° | 120 | 20.1 | 11.7 | 3.9 |
| Jul | 29° / 25° | 94 | 18.1 | 11.7 | 4.4 |
| Aug | 29° / 24° | 70 | 17 | 11.8 | 4.5 |
| Sep | 30° / 25° | 74 | 15.9 | 12 | 4.3 |
| Oct | 30° / 25° | 134 | 20.3 | 12.1 | 3.7 |
| Nov | 30° / 25° | 223 | 25.2 | 12.3 | 3.2 |
| Dec | 29° / 25° | 293 | 27.1 | 12.3 | 3.2 |
Cloud cover in Spring
The sky is clear or mostly clear about 12% of the time across spring.
Chance of precipitation in Spring
Cilegon gets around 431 mm of rain over 61 wet days across spring. The line is the day-by-day chance of measurable precipitation.
Humidity in Spring
Most of spring feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Spring
Winds average 7 km/h across spring.
Sunrise & sunset in Spring
Daylight runs from about 11 h 54 min in early September to 12 h 18 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Spring
Average shortwave solar energy reaching the ground each day across spring, about 5.7 kWh/m².
Hazard calendar for Cilegon
In spring, Cilegon overlaps its cyclone season. The full year is below, with each hazard's peak months called out.
Cilegon sits in the South Indian Ocean cyclone belt; the season peaks January–March.
Is spring a good time to visit Cilegon?
Our two travel scores rate spring for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
spring is a weaker month for outdoor sightseeing in Cilegon.
What to pack for Cilegon in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, Cilegon sees daytime highs around 30°C and nights near 25°C. Pack light clothes, rain gear and sun protection. About 61 days see rain.
Sea temperature near Cilegon in Spring
The nearest coast averages about 29°C across spring — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 29 | 29 | 29 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 30 | 29 |
| Comfort | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 29 | Tropical |
| Feb | 29 | Tropical |
| Mar | 29 | Tropical |
| Apr | 30 | Tropical |
| May | 30 | Tropical |
| Jun | 30 | Tropical |
| Jul | 29 | Tropical |
| Aug | 29 | Tropical |
| Sep | 29 | Tropical |
| Oct | 29 | Tropical |
| Nov | 30 | Tropical |
| Dec | 29 | Tropical |
UV index in Cilegon in Spring
Clear-sky midday UV across spring averages 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 13 | 13 | 15 | 11 | 9 | 8 | 9 | 10 | 9 | 11 | 6 | 12 |
| Level | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high | Very high | Very high | Extreme | High | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 13 | Extreme |
| Feb | 13 | Extreme |
| Mar | 15 | Extreme |
| Apr | 11 | Extreme |
| May | 9 | Very high |
| Jun | 8 | Very high |
| Jul | 9 | Very high |
| Aug | 10 | Very high |
| Sep | 9 | Very high |
| Oct | 11 | Extreme |
| Nov | 6 | High |
| Dec | 12 | Extreme |
Air quality in Cilegon in Spring
Average fine-particle pollution (PM2.5) through the year — so you can see where spring 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 16 | 18 | 17 | 24 | 36 | 33 | 35 | 37 | 36 | 33 | 22 | 14 |
| Level | Moderate | Moderate | Moderate | Moderate | Poor | Moderate | Poor | Poor | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 16 | Moderate |
| Feb | 18 | Moderate |
| Mar | 17 | Moderate |
| Apr | 24 | Moderate |
| May | 36 | Poor |
| Jun | 33 | Moderate |
| Jul | 35 | Poor |
| Aug | 37 | Poor |
| Sep | 36 | Poor |
| Oct | 33 | Moderate |
| Nov | 22 | Moderate |
| Dec | 14 | Moderate |
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.
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 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.