Long-term weather trends in Bontang: 30-day, 3-month and 12-month forecasts
Weather trend
Based on 18 years of archives
Calculated on 6 September 2026
Find long-term weather in Bontang, Indonesian Borneo (Kalimantan), with a 30-day trend, for the next 3 months and month-by-month over 12 months, calculated from 18 years of weather archives.
30-day weather forecast in Bontang, Indonesian Borneo (Kalimantan)
This summary helps quickly identify the major weather trends for the coming month in Bontang, Indonesian Borneo (Kalimantan), before checking the day-by-day calendar below.
Average temperature
28.9°C
Likely rainy days / week
4.8 days
Dominant weather type
rainy
41%
To remember
The expected temperature remains close to the normals, around 28.9°C on average. The rain looks close to usual levels, with about 4.8 rainy days per week. The dominant scenario remains rainy, with about 41% recurrence and a average confidence.
These long-term predictions are calculated from 18 years of observed weather in Bontang. They allow identification of probable trends derived from historical data, and are not short-term weather forecasts.
30-day weather calendar in Bontang, day by day
For each date, find a likely temperature range, a risk of rain, and the most frequent weather type.
| Date | Temperatures | Rain | Dominant weather | History |
|---|---|---|---|---|
|
September 30, 2026
|
27°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
66%
If rain:
light
|
rainy
38%
|
|
|
October 1, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
67%
If rain:
light
|
rainy
38%
|
|
|
October 2, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
68%
If rain:
light
|
rainy
39%
|
|
|
October 3, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
69%
If rain:
light
|
rainy
39%
|
|
|
October 4, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
71%
If rain:
light
|
rainy
40%
|
|
|
October 5, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
72%
If rain:
light
|
rainy
41%
|
|
|
October 6, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
73%
If rain:
light
|
rainy
42%
|
|
|
October 7, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
74%
If rain:
light
|
rainy
43%
|
|
|
October 8, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
74%
If rain:
light
|
rainy
43%
|
|
|
October 9, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
73%
If rain:
light
|
rainy
43%
|
|
|
October 10, 2026
|
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
|
Risk of rain
72%
If rain:
light
|
rainy
43%
|
|
|
October 11, 2026
|
26°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
70%
If rain:
light
|
rainy
42%
|
|
|
October 12, 2026
|
26°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
68%
If rain:
light
|
rainy
41%
|
|
|
October 13, 2026
|
26°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
67%
If rain:
light
|
rainy
40%
|
|
|
October 14, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
65%
If rain:
light
|
rainy
39%
|
|
|
October 15, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
64%
If rain:
light
|
rainy
38%
|
|
|
October 16, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
63%
If rain:
light
|
rainy
38%
|
|
|
October 17, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
63%
If rain:
light
|
rainy
38%
|
|
|
October 18, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
63%
If rain:
light
|
rainy
38%
|
|
|
October 19, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
64%
If rain:
light
|
rainy
39%
|
|
|
October 20, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
|
Risk of rain
65%
If rain:
light
|
rainy
40%
|
|
|
October 21, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
66%
If rain:
light
|
rainy
41%
|
|
|
October 22, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
68%
If rain:
light
|
rainy
42%
|
|
|
October 23, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
70%
If rain:
light
|
rainy
43%
|
|
|
October 24, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
72%
If rain:
light
|
rainy
44%
|
|
|
October 25, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
73%
If rain:
light
|
rainy
45%
|
|
|
October 26, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
73%
If rain:
light
|
rainy
46%
|
|
|
October 27, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
|
Risk of rain
74%
If rain:
light
|
rainy
46%
|
|
|
October 28, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
29.8°C
|
Risk of rain
74%
If rain:
light
|
rainy
46%
|
|
|
October 29, 2026
|
27°C /
31°C
Likely temperature:
28.0°C -
29.8°C
|
Risk of rain
74%
If rain:
light
|
rainy
46%
|
September 30, 2026
Temperatures
27°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
66%
If rain:
light
Dominant weather
rainy
38%
October 1, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
67%
If rain:
light
Dominant weather
rainy
38%
October 2, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
68%
If rain:
light
Dominant weather
rainy
39%
October 3, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
69%
If rain:
light
Dominant weather
rainy
39%
October 4, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
71%
If rain:
light
Dominant weather
rainy
40%
October 5, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
72%
If rain:
light
Dominant weather
rainy
41%
October 6, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
73%
If rain:
light
Dominant weather
rainy
42%
October 7, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
74%
If rain:
light
Dominant weather
rainy
43%
October 8, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
74%
If rain:
light
Dominant weather
rainy
43%
October 9, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
73%
If rain:
light
Dominant weather
rainy
43%
October 10, 2026
Temperatures
26°C /
31°C
Likely temperature:
27.8°C -
30.0°C
Rain
Risk of rain
72%
If rain:
light
Dominant weather
rainy
43%
October 11, 2026
Temperatures
26°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
70%
If rain:
light
Dominant weather
rainy
42%
October 12, 2026
Temperatures
26°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
68%
If rain:
light
Dominant weather
rainy
41%
October 13, 2026
Temperatures
26°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
67%
If rain:
light
Dominant weather
rainy
40%
October 14, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
65%
If rain:
light
Dominant weather
rainy
39%
October 15, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
64%
If rain:
light
Dominant weather
rainy
38%
October 16, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
63%
If rain:
light
Dominant weather
rainy
38%
October 17, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
63%
If rain:
light
Dominant weather
rainy
38%
October 18, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
63%
If rain:
light
Dominant weather
rainy
38%
October 19, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
64%
If rain:
light
Dominant weather
rainy
39%
October 20, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.3°C
Rain
Risk of rain
65%
If rain:
light
Dominant weather
rainy
40%
October 21, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
66%
If rain:
light
Dominant weather
rainy
41%
October 22, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
68%
If rain:
light
Dominant weather
rainy
42%
October 23, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
70%
If rain:
light
Dominant weather
rainy
43%
October 24, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
72%
If rain:
light
Dominant weather
rainy
44%
October 25, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
73%
If rain:
light
Dominant weather
rainy
45%
October 26, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
73%
If rain:
light
Dominant weather
rainy
46%
October 27, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
30.0°C
Rain
Risk of rain
74%
If rain:
light
Dominant weather
rainy
46%
October 28, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
29.8°C
Rain
Risk of rain
74%
If rain:
light
Dominant weather
rainy
46%
October 29, 2026
Temperatures
27°C /
31°C
Likely temperature:
28.0°C -
29.8°C
Rain
Risk of rain
74%
If rain:
light
Dominant weather
rainy
46%
This 30-day weather forecast in Bontang allows you to quickly identify the mildest, wettest, or most changeable stretches in the coming month.
Week-by-week weather trend in Bontang over 10 weeks
The maps below follow the actual calendar weeks, from Monday to Sunday, to identify the most favorable periods in the coming weeks in Bontang.
Week 40
28 September - 4 October 2026
rainy
39%
sunny
32%
clearings
27%
Likely temperature
26°C / 31°C
Probable rain
4.7 days -
31 mm
Week 41
5 - 11 October 2026
rainy
43%
sunny
30%
clearings
25%
Likely temperature
26°C / 31°C
Probable rain
5.1 days -
37 mm
Week 42
12 - 18 October 2026
rainy
39%
sunny
33%
clearings
26%
Likely temperature
26°C / 31°C
Probable rain
4.5 days -
31 mm
Week 43
19 - 25 October 2026
rainy
42%
sunny
28%
clearings
27%
Likely temperature
27°C / 31°C
Probable rain
4.8 days -
35 mm
Week 44
26 October - 1 November 2026
rainy
46%
sunny
26%
clearings
26%
Likely temperature
27°C / 31°C
Probable rain
5.1 days -
48 mm
Week 45
2 - 8 November 2026
rainy
47%
clearings
27%
sunny
23%
Likely temperature
27°C / 31°C
Probable rain
5.4 days -
43 mm
Week 46
9 - 15 November 2026
rainy
48%
clearings
26%
sunny
23%
Likely temperature
26°C / 30°C
Probable rain
5.8 days -
51 mm
Week 47
16 - 22 November 2026
rainy
44%
clearings
30%
sunny
22%
Likely temperature
26°C / 30°C
Probable rain
5.7 days -
48 mm
Week 48
23 - 29 November 2026
rainy
42%
clearings
29%
sunny
23%
cloudy
6%
Likely temperature
26°C / 30°C
Probable rain
5.6 days -
56 mm
Week 49
30 November - 6 December 2026
rainy
43%
clearings
31%
sunny
20%
cloudy
6%
Likely temperature
26°C / 30°C
Probable rain
5.9 days -
56 mm
3-month weather trend in Bontang
Temperatures, rain, sunshine and prevailing weather for the coming month and the following two months in Bontang, Indonesian Borneo (Kalimantan).
September 2026
rainy
37%
clearings
30%
sunny
28%
Likely temperature
27°C / 30°C
Average temperature
28.9°C
Probable rain
77 mm
Rainy days
19 days
Average sun/day
11.4 h
Average wind
12 km/h
Average humidity
82%
Cloud cover
35%
October 2026
rainy
41%
sunny
30%
clearings
26%
Likely temperature
27°C / 30°C
Average temperature
28.8°C
Probable rain
132 mm
Rainy days
22 days
Average sun/day
11.4 h
Average wind
12 km/h
Average humidity
84%
Cloud cover
40%
November 2026
rainy
46%
clearings
28%
sunny
23%
Likely temperature
27°C / 30°C
Average temperature
28.6°C
Probable rain
206 mm
Rainy days
24 days
Average sun/day
11.4 h
Average wind
11 km/h
Average humidity
84%
Cloud cover
38%
This 3-month weather trend in Bontang helps anticipate the next month and the two following for a stay, a departure, or seasonal planning.
Month-by-month weather forecast in Bontang over 12 months
Easily compare over 1 year the likely weather for each upcoming month in Bontang, Indonesian Borneo (Kalimantan) to choose the best time based on heat, rain, or sunshine.
September 2026
rainy
37%
clearings
30%
sunny
28%
27°C
30°C
77 mm
19 days
limited trust
October 2026
rainy
41%
sunny
30%
clearings
26%
27°C
30°C
132 mm
22 days
limited trust
November 2026
rainy
46%
clearings
28%
sunny
23%
27°C
30°C
206 mm
24 days
average confidence
December 2026
rainy
48%
clearings
31%
sunny
14%
cloudy
7%
26°C
30°C
174 mm
26 days
average confidence
January 2027
rainy
48%
clearings
31%
sunny
15%
cloudy
5%
26°C
29°C
256 mm
26 days
average confidence
February 2027
rainy
42%
clearings
26%
sunny
25%
cloudy
5%
26°C
29°C
141 mm
20 days
limited trust
March 2027
rainy
41%
clearings
34%
sunny
19%
26°C
29°C
190 mm
24 days
limited trust
April 2027
rainy
41%
clearings
29%
sunny
23%
cloudy
6%
26°C
30°C
215 mm
25 days
limited trust
May 2027
rainy
45%
clearings
27%
sunny
20%
cloudy
7%
27°C
30°C
176 mm
24 days
limited trust
June 2027
rainy
46%
clearings
28%
sunny
20%
cloudy
5%
26°C
30°C
142 mm
22 days
average confidence
July 2027
rainy
44%
clearings
30%
sunny
18%
cloudy
6%
26°C
29°C
113 mm
21 days
average confidence
August 2027
rainy
46%
clearings
29%
sunny
19%
26°C
30°C
107 mm
21 days
average confidence
This 12-month weather calendar in Bontang makes it easy to compare the warmest, driest, or sunniest periods.
Compare these forecasts with the weather archives of Bontang
To go further, consult the city's detailed weather archives and the available years to compare these trends with past observations.
Long-term weather forecast around of Bontang
Find the towns near of Bontang on the map and compare their long-term weather forecasts to choose the most favorable area.
Long-term weather forecast calculation method in Bontang
These long-term weather trends in Bontang are estimated from 18 years of observed weather. They are mainly useful for identifying the most favorable periods and do not replace short-term weather forecasts.
Number of years of history
18
Comparison window
target day +/- 7 days
Update
daily
Output type
weather trend based on history
How are these trends calculated
Same period, year after year
For each future day, we look at the comparable dates observed over 18 years, with a rolling window of 15 days around the target day.
More weight to recent years
The most recent years are weighted slightly more to better reflect recent changes in weather conditions.
How to read the prevailing weather
The prevailing weather corresponds to the most frequent weather scenario over the displayed period. The percentage indicates its estimated share, and the other weather types shown in smaller size display the possible secondary scenarios, especially useful in weekly or monthly forecasts.
Months are calculated separately
Monthly trends are calculated directly from historical months to avoid artificial daily accumulations.
How to read confidence levels
The confidence score summarizes how much the model runs converge on a stable weather scenario for the displayed period.
high confidence
70 to 100
Past years tell a fairly coherent story: temperatures, rainfall and weather type vary little around the dominant scenario.
average confidence
45 to 69
A clear trend exists, but with greater year-to-year variations. The result should be read as a probable direction.
limited trust
0 to 44
The archives are more scattered over this period. The displayed scenario remains useful as a reference, but it should be interpreted with caution.
In practice, confidence is generally more robust over months than over weeks, because longer periods smooth out weather variability more.
Limits to keep in mind
- This is a long-term trend based on historical data, not an operational weather forecast for a few days.
- Exceptional or very localized episodes may deviate significantly from the most likely scenario.
- Monthly trends are generally more reliable for choosing a period, while day-by-day detail is mainly used to refine pinpointing.