Cilegon weather in September
In September, Cilegon sees average daytime highs of 30°C and overnight lows near 25°C, with 74 mm of rain across 15.9 wet days and about 12 hours of daylight. It is the 3rd-warmest and 11th-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 17% of the time in September, and the air most often feels oppressive.
Daylight stretches from about 11 h 54 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Cilegon's 4th-clearest and 11th-windiest month. For the whole year in context, see Cilegon's year-round climate.
- Daytime high
- 30°
- 3rd warmest
- Overnight low
- 25°
- 3rd coldest
- Rainfall
- 74 mm
- 15.9 wet days
- Daylight
- 12 hours
- 5:51 AM – 5:49 PM
- Cloud cover
- 64%
- 4th clearest
- Wind
- 6 km/h
- 11th windiest
- Solar energy
- 6.03 kWh/m²
- Travel score
- 4.3
- 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 September
Day-to-day highs hold fairly steady near 30°C through the month.
A typical September day in Cilegon reaches about 30°C in the afternoon and slips back to 25°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, September runs on par with August and on par with October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 |
| Avg low (°C) | 24 | 24 | 24 | 24 | 24 | 24 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 25 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 30 | 24 |
| 2 | 30 | 24 |
| 3 | 30 | 24 |
| 4 | 30 | 24 |
| 5 | 30 | 24 |
| 6 | 30 | 24 |
| 7 | 30 | 25 |
| 8 | 30 | 25 |
| 9 | 30 | 25 |
| 10 | 30 | 25 |
| 11 | 30 | 25 |
| 12 | 30 | 25 |
| 13 | 30 | 25 |
| 14 | 30 | 25 |
| 15 | 30 | 25 |
| 16 | 30 | 25 |
| 17 | 30 | 25 |
| 18 | 30 | 25 |
| 19 | 30 | 25 |
| 20 | 30 | 25 |
| 21 | 30 | 25 |
| 22 | 30 | 25 |
| 23 | 30 | 25 |
| 24 | 30 | 25 |
| 25 | 30 | 25 |
| 26 | 30 | 25 |
| 27 | 30 | 25 |
| 28 | 30 | 25 |
| 29 | 30 | 25 |
| 30 | 30 | 25 |
How September really feels in Cilegon
Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Cilegon weather by month
How September compares with the rest of the year at a glance. September is the 3rd-warmest and 11th-wettest month here — the current month is highlighted below.
| 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 September
The sky is clear or mostly clear about 17% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 26% of September, with mostly cloudy or overcast conditions the remaining 57%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 48 | 48 | 48 | 48 | 47 | 47 | 47 | 47 | 46 | 46 | 45 | 45 | 45 | 44 | 43 | 43 | 42 | 42 | 41 | 40 | 40 | 40 | 40 | 40 | 40 | 39 | 39 | 39 | 38 | 38 |
| Cloudier (%) | 52 | 52 | 52 | 52 | 53 | 53 | 53 | 53 | 54 | 54 | 55 | 55 | 55 | 56 | 57 | 57 | 58 | 58 | 59 | 60 | 60 | 60 | 60 | 60 | 60 | 61 | 61 | 61 | 62 | 62 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 48 | 52 |
| 2 | 48 | 52 |
| 3 | 48 | 52 |
| 4 | 48 | 52 |
| 5 | 47 | 53 |
| 6 | 47 | 53 |
| 7 | 47 | 53 |
| 8 | 47 | 53 |
| 9 | 46 | 54 |
| 10 | 46 | 54 |
| 11 | 45 | 55 |
| 12 | 45 | 55 |
| 13 | 45 | 55 |
| 14 | 44 | 56 |
| 15 | 43 | 57 |
| 16 | 43 | 57 |
| 17 | 42 | 58 |
| 18 | 42 | 58 |
| 19 | 41 | 59 |
| 20 | 40 | 60 |
| 21 | 40 | 60 |
| 22 | 40 | 60 |
| 23 | 40 | 60 |
| 24 | 40 | 60 |
| 25 | 40 | 60 |
| 26 | 39 | 61 |
| 27 | 39 | 61 |
| 28 | 39 | 61 |
| 29 | 38 | 62 |
| 30 | 38 | 62 |
Chance of precipitation in September
Cilegon gets around 74 mm of rain over 15.9 wet days in September. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 53% and peaks near 56% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 56 | 56 | 56 | 55 | 55 | 54 | 54 | 53 | 53 | 53 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 53 | 53 | 53 | 53 | 53 | 54 | 54 | 54 |
| Rain chance (%) | |
|---|---|
| 1 | 56 |
| 2 | 56 |
| 3 | 56 |
| 4 | 55 |
| 5 | 55 |
| 6 | 54 |
| 7 | 54 |
| 8 | 53 |
| 9 | 53 |
| 10 | 53 |
| 11 | 52 |
| 12 | 52 |
| 13 | 52 |
| 14 | 52 |
| 15 | 52 |
| 16 | 52 |
| 17 | 52 |
| 18 | 52 |
| 19 | 52 |
| 20 | 52 |
| 21 | 52 |
| 22 | 52 |
| 23 | 53 |
| 24 | 53 |
| 25 | 53 |
| 26 | 53 |
| 27 | 53 |
| 28 | 54 |
| 29 | 54 |
| 30 | 54 |
Humidity in September
Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the oppressive band about 88% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Muggy (%) | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Oppressive (%) | 89 | 89 | 89 | 89 | 89 | 89 | 88 | 89 | 89 | 89 | 89 | 90 | 90 | 90 | 90 | 89 | 89 | 88 | 88 | 87 | 87 | 87 | 86 | 85 | 85 | 84 | 84 | 83 | 83 | 83 |
| Miserable (%) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 9 | 9 | 10 | 10 | 11 | 11 | 12 | 13 | 14 | 14 | 15 | 15 | 16 | 16 | 16 |
| Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|
| 1 | 2 | 89 | 9 |
| 2 | 2 | 89 | 9 |
| 3 | 2 | 89 | 9 |
| 4 | 2 | 89 | 9 |
| 5 | 2 | 89 | 9 |
| 6 | 2 | 89 | 9 |
| 7 | 3 | 88 | 9 |
| 8 | 3 | 89 | 8 |
| 9 | 3 | 89 | 8 |
| 10 | 3 | 89 | 8 |
| 11 | 3 | 89 | 8 |
| 12 | 2 | 90 | 8 |
| 13 | 2 | 90 | 8 |
| 14 | 2 | 90 | 8 |
| 15 | 2 | 90 | 8 |
| 16 | 2 | 89 | 9 |
| 17 | 2 | 89 | 9 |
| 18 | 2 | 88 | 10 |
| 19 | 2 | 88 | 10 |
| 20 | 2 | 87 | 11 |
| 21 | 2 | 87 | 11 |
| 22 | 1 | 87 | 12 |
| 23 | 1 | 86 | 13 |
| 24 | 1 | 85 | 14 |
| 25 | 1 | 85 | 14 |
| 26 | 1 | 84 | 15 |
| 27 | 1 | 84 | 15 |
| 28 | 1 | 83 | 16 |
| 29 | 1 | 83 | 16 |
| 30 | 1 | 83 | 16 |
Wind in September
Winds average 6 km/h in September.
Across September, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 6 | calm |
| 2 | 6 | calm |
| 3 | 6 | calm |
| 4 | 6 | calm |
| 5 | 6 | calm |
| 6 | 6 | calm |
| 7 | 6 | calm |
| 8 | 6 | calm |
| 9 | 6 | calm |
| 10 | 6 | calm |
| 11 | 6 | calm |
| 12 | 6 | calm |
| 13 | 6 | calm |
| 14 | 6 | calm |
| 15 | 6 | calm |
| 16 | 6 | calm |
| 17 | 6 | calm |
| 18 | 6 | calm |
| 19 | 6 | calm |
| 20 | 6 | calm |
| 21 | 6 | calm |
| 22 | 6 | calm |
| 23 | 6 | calm |
| 24 | 6 | calm |
| 25 | 6 | calm |
| 26 | 6 | calm |
| 27 | 6 | calm |
| 28 | 6 | calm |
| 29 | 6 | calm |
| 30 | 6 | calm |
Sunrise & sunset in September
Daylight runs from about 11 h 54 min at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 6 minutes over September. Sunrise moves from 5:59 AM to 5:44 AM, and sunset from 5:52 PM to 5:46 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 11.9 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 |
| Sunrise (AM) | 5:59 | 5:58 | 5:58 | 5:57 | 5:57 | 5:56 | 5:56 | 5:55 | 5:55 | 5:54 | 5:54 | 5:53 | 5:53 | 5:52 | 5:52 | 5:51 | 5:51 | 5:50 | 5:49 | 5:49 | 5:48 | 5:48 | 5:47 | 5:47 | 5:46 | 5:46 | 5:45 | 5:45 | 5:44 | 5:44 |
| Sunset (PM) | 5:52 | 5:52 | 5:52 | 5:51 | 5:51 | 5:51 | 5:51 | 5:51 | 5:51 | 5:50 | 5:50 | 5:50 | 5:50 | 5:50 | 5:49 | 5:49 | 5:49 | 5:49 | 5:49 | 5:48 | 5:48 | 5:48 | 5:48 | 5:48 | 5:47 | 5:47 | 5:47 | 5:47 | 5:47 | 5:46 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 11.9 | 5:59 | 5:52 |
| 2 | 11.9 | 5:58 | 5:52 |
| 3 | 11.9 | 5:58 | 5:52 |
| 4 | 11.9 | 5:57 | 5:51 |
| 5 | 11.9 | 5:57 | 5:51 |
| 6 | 11.9 | 5:56 | 5:51 |
| 7 | 11.9 | 5:56 | 5:51 |
| 8 | 11.9 | 5:55 | 5:51 |
| 9 | 11.9 | 5:55 | 5:51 |
| 10 | 11.9 | 5:54 | 5:50 |
| 11 | 11.9 | 5:54 | 5:50 |
| 12 | 11.9 | 5:53 | 5:50 |
| 13 | 12.0 | 5:53 | 5:50 |
| 14 | 12.0 | 5:52 | 5:50 |
| 15 | 12.0 | 5:52 | 5:49 |
| 16 | 12.0 | 5:51 | 5:49 |
| 17 | 12.0 | 5:51 | 5:49 |
| 18 | 12.0 | 5:50 | 5:49 |
| 19 | 12.0 | 5:49 | 5:49 |
| 20 | 12.0 | 5:49 | 5:48 |
| 21 | 12.0 | 5:48 | 5:48 |
| 22 | 12.0 | 5:48 | 5:48 |
| 23 | 12.0 | 5:47 | 5:48 |
| 24 | 12.0 | 5:47 | 5:48 |
| 25 | 12.0 | 5:46 | 5:47 |
| 26 | 12.0 | 5:46 | 5:47 |
| 27 | 12.0 | 5:45 | 5:47 |
| 28 | 12.0 | 5:45 | 5:47 |
| 29 | 12.0 | 5:44 | 5:47 |
| 30 | 12.0 | 5:44 | 5:46 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 6.03 kWh/m² — the sunniest month for solar.
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 — September's 6.03 kWh/m² sits near the top of that range.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.8 | 5.8 | 5.8 | 5.9 | 5.9 | 5.9 | 5.9 | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | 6.0 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.1 | 6.0 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 5.8 | Bright |
| 2 | 5.8 | Bright |
| 3 | 5.8 | Bright |
| 4 | 5.9 | Bright |
| 5 | 5.9 | Bright |
| 6 | 5.9 | Bright |
| 7 | 5.9 | Bright |
| 8 | 6.0 | Bright |
| 9 | 6.0 | Bright |
| 10 | 6.0 | Bright |
| 11 | 6.0 | Intense |
| 12 | 6.0 | Intense |
| 13 | 6.0 | Intense |
| 14 | 6.0 | Intense |
| 15 | 6.0 | Intense |
| 16 | 6.1 | Intense |
| 17 | 6.1 | Intense |
| 18 | 6.1 | Intense |
| 19 | 6.1 | Intense |
| 20 | 6.1 | Intense |
| 21 | 6.1 | Intense |
| 22 | 6.1 | Intense |
| 23 | 6.1 | Intense |
| 24 | 6.1 | Intense |
| 25 | 6.1 | Intense |
| 26 | 6.1 | Intense |
| 27 | 6.1 | Intense |
| 28 | 6.1 | Intense |
| 29 | 6.1 | Intense |
| 30 | 6.0 | Intense |
Hazard calendar for Cilegon
None of Cilegon's seasonal hazards are active in September. 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.
Is September a good time to visit Cilegon?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a reasonable time to visit Cilegon for sightseeing.
What to pack for Cilegon in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Cilegon sees daytime highs around 30°C and nights near 25°C. Pack light clothes, rain gear and sun protection. About 16 days see rain.
Sea temperature near Cilegon in September
The nearest coast averages about 29°C in September — 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 September
Clear-sky midday UV in September 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.
| 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 September
Average fine-particle pollution (PM2.5) through the year — so you can see where September 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. 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).