Mount Rinjani Temperature In December – When international travelers plan a hike to Mount Rinjani, one of the first questions they ask is: “What is the temperature like in December, and will the weather allow me to hike safely?”
December marks the beginning of the rainy season in Lombok, and many hikers try to determine the best possible window to book their flights. Weather forecasts become essential because the amount of rain, cloud cover, and temperature fluctuations can significantly influence visibility, trail conditions, and comfort during the ascent.
Although Mount Rinjani has several official entrances, the Sembalun Route remains the most popular starting point, especially for those aiming to reach the summit. The temperature and weather conditions around Sembalun Village do not fully represent the entire mountain—after all, Rinjani spans various elevations and microclimates.
However, the Sembalun forecast still provides a reliable overview of how December typically behaves. Using monthly weather data from AccuWeather as a reference, let’s explore a detailed breakdown of the Mount Rinjani Temperature In December week by week.
Mount Rinjani Temperature In December Based on Sembalun Route
While Sembalun sits far below the summit and cannot reflect all mountain conditions, the area’s December forecast offers a helpful general picture for hikers planning their visit. Below is a week-by-week breakdown based on AccuWeather’s monthly overview.
1. First Week of December – Warm Days With Early-Month Showers
During the first week, the weather tends to fluctuate between daytime warmth and cooler conditions at night.
Average temperature:
- 29–32°C RealFeel (representing how hot the air feels under direct sunlight)
- 26–27°C RealFeel Shade (representing conditions in shaded areas)
Weather condition:
- Expect short showers on December 1–2, followed by a mix of cloudy and partly sunny days.
For travelers arriving early in the month, this week still offers a fair number of brighter days, though occasional rainfall remains possible. The humidity begins increasing, which may affect how hot the temperature feels during the hike from Sembalun to the base camp.
2. Second Week of December – Frequent Rain With Isolated Thunderstorms
This week marks a more apparent transition into rainy conditions.
Weather condition:
- Rain is expected almost every day, with varying intensity.
- On December 9, forecasts predict heavy showers and thunderstorms, which may affect visibility and trail safety. Thankfully, the weather tends to improve slightly toward the weekend.
Average temperature:
- 27–30°C RealFeel
- 25–27°C RealFeel Shade
The second week is generally wetter and cloudier, creating a higher chance of slippery trails. If you plan to trek during this week, relying on a trekking organizer becomes extremely important to determine whether the weather window is safe.
3. Third Week of December – Bright Start, Rainier Midweek
The third week begins with promising conditions.
Weather condition:
- Early days are generally cloudy or partly sunny, offering better visibility.
- Mid- to late-week might bring short showers, steady rain, and occasional rainy spells.
Average temperature:
- 28–32°C RealFeel
- 25–27°C RealFeel Shade
This pattern is typical of early monsoon: the mornings may look bright, but late afternoon showers appear without much warning. Many hikers still choose this period due to the increased chance of manageable morning weather.
4. Fourth Week of December – Rain-Dominated Weather
Toward the end of December, rain becomes more frequent and consistent.
Weather condition:
- Daytime rain dominates the week, while the weekend may bring a short break with cloudy skies.
- Entering the last days of the month, daily rain becomes the dominant condition.
Average temperature:
- 26–31°C RealFeel
- 25–29°C RealFeel Shade
Despite the increased rainfall, December hiking is still possible as long as hikers choose the right dates, pack proper rain gear, and coordinate with local organizers. The biggest challenge is not extreme cold but rather the unpredictability of tropical rainstorms.
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Read also: Mount Rinjani Tour Prices & Packages for Couples or Groups
Mount Rinjani Temperature In December During the Rainy Season
Forecasting the exact Mount Rinjani Temperature In December at the summit or crater rim is difficult because high-altitude weather changes rapidly. However, based on general rainy-season patterns and past observations, hikers can expect:
Summit temperature:
- 5°C to 10°C during the dry moments
- 2°C to 6°C during or after rainfall, especially when accompanied by strong winds
Crater rim temperature (Sembalun or Senaru side):
- 8°C to 12°C in cloudy or partly sunny weather
- 6°C to 10°C in rainy or windy conditions
Wind chill can make these temperatures feel significantly colder, so RealFeel values at higher elevations may drop below 0°C during the heaviest rain or storms. Even during the rainy season, the summit can remain cold enough for frost-like conditions early in the morning.
These elements mean you must bring a thermal jacket, gloves, waterproof shoes, long layers, and proper rain protection. The dramatic temperature drop from Sembalun Village to the rim often surprises hikers who assume that tropical mountains remain warm throughout the year.
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Read also: Can You Climb Mount Rinjani in December? Pros and Cons
You Can Still Hike Mount Rinjani Safely in December!
Even though December marks the beginning of the rainy season, you can still hike Mount Rinjani safely—as long as you prepare properly. Hiking in the rain requires more than determination. You must:
- Check updated weather forecasts
- Monitor official trail status
- Use a certified trekking organizer to handle permits, timing, and safety considerations
Because you are an international traveler, these steps are best managed by a local professional. Weather assessments, ranger updates, and logistical arrangements in Lombok can change quickly, so having a trusted organizer ensures you stay informed and protected.
For personalized guidance and safer planning, contact Hiking Mount Rinjani, one of the official and reliable trekking organizers operating around the mountain. They have supported trekking activities since 2015, and their team consists of experienced guides, skilled porters, and well-maintained camping equipment.
Their services include:
- Comfortable sleeping tents
- Warm high-calorie meals
- Hot drinks during cold mornings
- Safe route guidance
- Porter support for carrying camping gear
They also provide airport pickup, transportation to your hotel, and assistance in choosing dates that match your flight schedule and preferred weather conditions.
Your main responsibility is simply preparing yourself physically and bringing essential personal items such as: A warm insulated jacket, waterproof gear (poncho, bag cover, dry bag), sturdy waterproof hiking shoes, headlamp and extra socks.
Everything else—from campsite preparation to safety management—is handled by the trekking organizer.
If you want to consult about hiking Mount Rinjani in December or need help choosing the ideal date, simply contact Hiking Mount Rinjani via the WhatsApp link below.