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Ijen

Mountain

A volcanic complex in East Java famous for its acidic turquoise crater lake and nighttime sulfur 'blue fire' visible to early‑morning visitors; hikers also see active sulfur mining at the crater rim.

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Ijen essentials

Address: Ijen (Kawah Ijen) caldera, Banyuwangi / Bondowoso, East Java, Indonesia
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About Ijen

Ijen is a volcanic complex on the Ijen Plateau in East Java, Indonesia, best known for its central crater, Kawah Ijen, which contains a highly acidic turquoise lake and exposed sulfur deposits. The crater is the focus of both geological interest and local sulfur-mining activity.

The crater area offers dramatic color contrasts between the turquoise lake, yellow sulfur stains and dark volcanic rock; there are designated trails and viewpoints around the rim. A nocturnal phenomenon known as “blue fire” - flames caused by burning sulfur gases - is visible before dawn and attracts many visitors.

Local miners work the sulfur deposits inside the crater, extracting solidified sulfur and carrying loads up the rim to the base, and visitors should be aware of hazardous gases and steep trails. gas masks are commonly recommended for close approaches to the crater.

The Ijen complex is a product of volcanic activity in East Java; the crater hosts longstanding small-scale sulfur extraction that has continued into the present. The striking lake coloration results from hydrothermal alteration and the lake’s high acidity.

Ijen lies on the eastern end of Java in East Java province on the Ijen Plateau, within reach of Banyuwangi and Bondowoso regencies and commonly visited from nearby towns and regional transport hubs.

  • Blue fire viewing: The site is famous for the nocturnal ‘blue fire’ phenomenon, a result of burning sulfur gases visible before dawn and most clearly seen during pre-dawn hours.

What to See#

  • Kawah Ijen crater lake and sulfur deposits: Kawah Ijen crater containing an acidic turquoise lake and large exposed sulfur deposits worked by miners; the crater is the central feature of the Ijen volcanic complex.
  • Crater rim trails and viewing points: Trails and observation points around the crater rim popular for sunrise and pre-dawn visits to see the crater and the volcanic blue fire phenomenon.
When to Go

Best Time to Visit Ijen

Visit during the dry season (roughly April-October) for the most reliable conditions for hiking to the Ijen crater and viewing the blue fire.

Dry season (best for hiking and views)
Apr-Oct · 10-25°C (crater rim)
Drier trails and clearer skies make early-morning hikes to see the crater and blue fire much more reliable.
Wet season (more difficult)
Nov-Mar · 15-28°C (lower elevations); crater area often cooler and wet
Frequent rain makes trails slippery and can obscure views; conditions for the night/early-morning trek are less predictable.

Weather & Climate near Ijen

Climate

Ijen's climate is classified as Tropical Rainforest - Tropical Rainforest climate with consistently warm temperatures year-round. Temperatures range from 18°C to 28°C. Heavy rainfall (2478 mm/year), wettest in January.

Air Quality: AQI 48 Good
Best Time to Visit
AugustSeptemberJuly
Temperature & Rainfall
Temperature Range
34°
Warmest Month
20°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January Good 19° - 27° 23° 384 mm overcast 82% 2.4 m/s 2.6 extreme 12.4h
February Good 19° - 27° 23° 322 mm overcast 82% 1.9 m/s 2.7 extreme 12.3h
March Good 19° - 27° 23° 333 mm partly cloudy 82% 1.9 m/s 2.6 extreme 12.0h
April Very Good 19° - 27° 23° 210 mm partly cloudy 82% 1.7 m/s 2.4 extreme 11.8h
May Very Good 19° - 27° 23° 177 mm some cloud 82% 1.8 m/s 2.1 extreme 11.6h
June Excellent 18° - 26° 22° 106 mm some cloud 82% 1.7 m/s 1.9 very high 11.5h
July Excellent 18° - 26° 22° 85 mm some cloud 80% 1.6 m/s 1.9 very high 11.6h
August Excellent 18° - 26° 22° 49 mm mostly sunny 78% 1.4 m/s 2.3 extreme 11.7h
September Excellent 18° - 27° 23° 80 mm mostly sunny 77% 2.2 m/s 2.6 extreme 11.9h
October Very Good 19° - 28° 23° 149 mm some cloud 76% 1.9 m/s 2.7 extreme 12.2h
November Good 20° - 28° 24° 250 mm partly cloudy 78% 2.3 m/s 2.6 extreme 12.4h
December Good 19° - 27° 23° 333 mm overcast 81% 2.1 m/s 2.4 extreme 12.5h
Getting There & Around

How to Get to Ijen

Ijen is reached most commonly from Banyuwangi (East Java). Drive from Banyuwangi to the Paltuding trailhead/parking area at the foot of Ijen - the road journey takes about 1.5-2 hours (roughly 40-50 km) depending on the route and traffic. From the Paltuding car park there is a steep hike of about 3-4 km (typically 1.5-2 hours) up to the crater rim; guided tours and local transport to the trailhead are widely available from Banyuwangi.

Tips for Visiting Ijen

  • To see the famous blue fire you must start the hike in the very early hours (typically around 00:30-02:00 depending on season) so you reach the crater before dawn; plan transport to the Paltuding trailhead from Banyuwangi the day before.
  • Hire a local guide and obtain or rent a gas mask at the trailhead-sulfur fumes can be hazardous, and guides also handle permits and know the safest viewing spots.
  • Stay for sunrise after the blue flame phase: many visitors leave immediately after seeing the flames but the crater rim offers dramatically different light and views once the sun rises, and arriving well before dawn avoids midday crowding.