CLIMATE (Part I)
3.1 Introduction
3.2 Climate in the Data Dictionary
3.3 Climate Data
3.3.1 Temperature Distribution
3.3.2 Rainfall Distribution
3.3.3 Wind
CLIMATE (Part II) (Wind Data Tables & Graphs)
CLIMATE (Part III)
3.3.4 Relative Humidity
3.3.5 Sunshine
3.3.6 Evaporation
3.3.7 Flood and Drought Prone Areas
3.3.8 Haze
3.4 Information Issues
3.4.1 Issues related to parameters
3.5 ICZM Issues Arising
3.5.1 Issues related to geographical distribution (spatial)
3.5.2 Issues related to seasonal variability (temporal)
3.5.3 Issues related to annual variability (trend)

Previous ChapterContentsNext

3  Climate (Part III)

3.3.4  Relative Humidity

Seasonal Variability: The relative humidity at the meteorological stations37 was fairly high and constant throughout the year within the period of data from 1990 to 1995 (Figure 13 and Table 15). This characteristic is expected of an area within an equatorial region. In addition to this, all the stations are located along the coastal area of Sabah.

Geographical Variability: The comparison of data could only be carried out among four stations due to the unavailability of information from the Kudat station. As observed in Figure 13 and Table 15, Tawau recorded the highest average of monthly mean relative humidity of 87% in December. The lowest average of monthly mean relative humidity was in Kota Kinabalu at 79% (August). Throughout the year, Tawau in particular, recorded relatively higher relative humidity compared to the rest of the stations.

Annual Variability: Figure 14 and Table 16 shows that the annual variability of relative humidity in Sabah from 1990 to 1995 was low. The relative humidity from year to year was fairly constant, as with the seasonal observation.

Figure 13: Average of Monthly Mean Relative Humidity (%) for Kota Kinabalu, Sandakan, Tawau and Labuan (1990 – 1995)

Table 15: Average and Standard Deviation of Monthly Mean Relative Humidity (%) for Kota Kinabalu, Sandakan, Tawau and Labuan (1990 – 1995)

MonthKOTA KINABALU SANDAKANTAWAULABUAN
January81.282.484.183.3
February80.981.984.483.9
March80.080.683.982.6
April79.480.384.182.2
May81.280.685.083.3
June79.780.585.582.4
July79.580.785.082.4
August79.281.284.781.6
September80.281.984.382.8
October81.982.884.883.6
November83.084.786.084.0
December82.385.487.283.4
Average80.781.984.983.0
Standard Deviation1.21.71.00.7

Source: Meteorological Department, Sabah

Table 16: Annual Average of Monthly Mean Relative Humidity (%) for Kota Kinabalu, Sandakan, Tawau and Labuan (1990 – 1995)

199019911992199319941995
AverageAverageAverageAverageAverageAverage
KOTA KINABALU80.380.780.280.780.981.4
SANDAKAN80.682.080.182.483.782.6
TAWAU84.283.885.784.484.786.7
LABUAN82.383.282.483.383.083.6
199019911992199319941995
Standard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard Deviation
KOTA KINABALU1.61.92.12.32.01.8
SANDAKAN1.91.93.12.01.72.3
TAWAU0.82.32.81.11.11.1
LABUAN1.71.51.61.91.41.2

Source: Meteorological Department, Sabah

         

Figure 14: Annual Average of Monthly Mean Relative Humidity (%) for Kota Kinabalu, Sandakan, Tawau and Labuan (1990 – 1995)

3.3.5  Sunshine

Seasonal Variability: As shown in Figure 15, the hours of sunshine within a day peaked during the months of March, April and May. However, there was a gradual decrease of sunshine hours per day towards the end of the year. Generally, there was a moderate variability of sunshine hours throughout the year from 1990 to 1997 (Table 17).

Geographical Variability: Kudat, which is located at the northern tip of Sabah, and Sandakan at the eastern fringe, experienced relative longer hours of sunshine particularly in the months of April and May within the period of data (Figure 15). Kudat registered the longest average of monthly mean sunshine hours of about 9.5 hours per day in April. The same station and Sandakan recorded the shortest hours of 5.5 per day in December.

Annual Variability: As shown in Figure 16 and Table 18, the annual variability of the average monthly mean sunshine hours within a day from 1990 to 1997 was moderate.

Figure 15: Average of Monthly Mean Sunshine Hours per Day for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

Table 17: Average of Monthly Mean Sunshine Hours per Day for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

MONTHKOTA KINABALUSANDAKANKUDATTAWAULABUAN
JANUARY6.96.06.36.57.5
FEBRUARY 7.26.76.96.47.4
MARCH8.17.98.67.38.0
APRIL8.49.29.57.78.3
MAY7.58.78.97.17.8
JUNE7.07.77.56.97.6
JULY6.47.66.87.07.0
AUGUST6.67.66.97.17.2
SEPTEMBER5.76.76.36.26.1
OCTOBER6.26.86.66.76.7
NOVEMBER6.76.85.97.27.4
DECEMBER6.55.55.56.16.9
Average6.97.37.16.87.3
Standard Deviation0.81.11.20.50.6

Source: Meteorological Department, Sabah

Table 18: Annual Average of Monthly Mean Sunshine Hours for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

19901991199219931994199519961997
AverageAverageAverageAverageAverageAverageAverageAverage
KOTA KINABALU7.46.87.37.06.76.66.57.2
SANDAKAN7.77.27.67.66.87.16.87.2
KUDAT7.67.17.67.26.77.16.57.3
TAWAU 6.56.57.27.36.86.76.57.3
LABUAN7.87.27.57.57.27.17.07.5
19901991199219931994199519961997
Standard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard Deviation
KOTA KINABALU1.11.21.01.01.01.41.31.6
SANDAKAN1.11.31.60.91.11.41.71.6
KUDAT1.21.61.71.51.01.81.91.7
TAWAU 0.70.71.00.51.00.91.01.2
LABUAN1.20.91.00.91.01.21.11.4

Source: Meteorological Department, Sabah

Figure 16: Annual Average of Monthly Mean Sunshine Hours for Kota Kinabalu,Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

 

3.3.6  Evaporation

Seasonal Variability: The records of the monthly mean evaporation from 1990 to 1997 shows that, relative to the other evaporation readings, the highest rate of evaporation per day occurred between March and May (Figure 17). During this period, it was identified that the average monthly mean sunshine hours were also the highest (Figure 15). The rate of evaporation generally decreased towards the end of the year. The period of decreasing evaporation rate corresponded to the period of Northeast Monsoon, which usually brings a substantial amount of rainfall to most parts of Sabah.

Geographical Variability: The average of the monthly mean evaporation rate per day in all the stations was similar, except Tawau (Figure 17 and Table 19). The maximum average of monthly mean evaporation rate during the period of study was recorded at 5.5 mm per day in Kudat (April). The variability of evaporation rates by stations was moderate.

Annual Variability: Annually, there was a moderate variability of evaporation rates observed from 1990 to 1997 (Figure 18). Tawau, in particular, experienced relatively lower annual average of monthly mean evaporation rates compared to the rest of the stations.

Figure 17: Average of Monthly Mean Evaporation (mm per day) for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

Table 19: Average of Monthly Mean Evaporation (mm per day) for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

MONTHKOTA KINABALUSANDAKANKUDATTAWAULABUAN
JANUARY4.44.03.93.44.6
FEBRUARY 4.54.44.23.74.6
MARCH4.85.35.14.35.0
APRIL4.95.45.54.45.0
MAY4.85.05.23.84.7
JUNE4.74.74.73.74.4
JULY4.64.54.53.74.1
AUGUST4.74.64.53.94.6
SEPTEMBER4.54.54.64.04.3
OCTOBER4.54.24.43.94.3
NOVEMBER4.43.93.53.74.4
DECEMBER4.43.93.53.24.2
Average4.64.54.53.84.5
Standard Deviation0.20.50.60.30.3

Source: Meteorological Department, Sabah

Table 20: Annual Average of Monthly Mean Evaporation (mm per day) for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

19901991199219931994199519961997
AverageAverageAverageAverageAverageAverageAverageAverage
KOTA KINABALU4.64.64.74.74.54.64.44.7
SANDAKAN4.74.65.04.64.34.44.24.4
KUDAT4.84.64.94.44.34.44.14.4
TAWAU3.83.84.03.93.63.73.64.0
LABUAN4.94.74.84.44.24.34.24.4
19901991199219931994199519961997
Standard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard DeviationStandard Deviation
KOTA KINABALU0.40.30.30.30.20.20.30.3
SANDAKAN0.70.61.00.50.30.60.60.7
KUDAT0.70.60.90.70.41.00.80.7
TAWAU0.40.50.70.40.50.40.60.6
LABUAN0.60.50.50.50.40.40.40.4

Figure 18: Annual Average of Monthly Mean Evaporation (mm per day) for Kota Kinabalu, Sandakan, Kudat, Tawau and Labuan (1990 – 1997)

3.3.7  Flood and Drought Prone Areas

The Department of Drainage and Irrigation, Sabah prepared a report of the flood-prone areas in Sabah for the year 1996. Nine districts were identified as flood-prone areas, as shown in Table 21. The map of flood prone areas in Sabah (1996) is presented in Figure 35.

Table 21: Flood-Prone Areas in Sabah, 1996

No.DistrictEstimated Flood-Prone Area (km2)
1.Beaufort16.0
2.Tenom14.0
3.Keningau7.0
4.Kinabatangan17.0
5.Kota Marudu8.0
6.Papar5.0
7.Penampang1.5
8.Kota Kinabalu1.0
9.

Kota Belud

1.5
TOTAL71.0

Source: Department of Drainage and Irrigation, Sabah, 1996

In 1996, the flood-prone areas reported in Sabah were identified as areas within the vicinity of water sources, such as rivers. The flood-prone area in the Kinabatangan district was estimated at about 17 km2, which was the largest area affected in 1996.

West Coast districts that were flooded in 1996 were Kota Kinabalu, Papar, Penampang, Kota Belud and Beaufort. However, the areas inundated with water were less than 5 km2 for each district, except for Beaufort, which suffered a total flooded area of 16 km2.

To the north, the estimated area affected by flood in Kota Marudu was reported at approximately 8 km2. In the interior region, the flood-prone areas in Tenom and Keningau were estimated at 14 km2 and 7 km2, respectively.

No recent data (e.g. 1998) of flooding occurrence has been recorded, but, generally, the areas identified in 1996 still face similar problems when the event occurs.

A few areas in the West Coast were identified as areas with water resources problem earlier this year. Towns such as Kuala Penyu, Sipitang, Papar, Kota Belud, Keningau and Tuaran encountered a severe water shortage problem towards the end of 1997 and the beginning of 1998. At the time of writing, detailed data on the drought affected areas were not available.

3.3.8  Haze

Haze is primarily caused by collective and excessive act of burning such as forest fires and open burning. The recent haze problem encountered simultaneously by Malaysia and other neighbouring countries such as Indonesia, Singapore and Indonesia showed that it is a problem that knows no bound.

The prolonged dry season was identified as the main reason of the fire and haze problem. However, anthropogenic activities such forest clearing by burning and waste burning have been described as the main culprits that have exacerbated the problems.

Being aware of the potential health threats and other problems caused by haze, the Government has set up monitoring stations in all major towns in Malaysia, including Kota Kinabalu to record the Air Pollution Index (Table 22). Restrictions on open burning and forest fires caused by anthropogenic activities were made more stringent by the Department of Environment.

However, at present, data on air pollution index of the major towns in Sabah are not available to enable any trend analyses to be carried out for the purpose of this chapter.

Table 22: Air Pollution Index (API)

API IndexCondition
0 – 50Good
51-100Moderate
101-200Unhealthy
201-300Very unhealthy
301-500Hazardous

Source: Department of Environment, Malaysia

3.4  Information Issues

3.4.1  Issues related to parameters

Trend and variability analyses of the available records of some of the parameters for climate monitoring are difficult due to the limited availability of data. If parameters are monitored at the same period at the meteorological stations, their values and uses would be greatly enhanced.

Temperature: The periods of the historical temperature data provided for all stations are not the same. Hence, a trend analysis of temperature distribution of the five stations could not be carried out.

Rainfall: Specifically for Kudat, the historical rainfall data are not available. Data of the maximum rainfall per month are not available for all the stations.

Relative Humidity: The historical relative humidity data are available for all the stations but the period of data, as with the historical temperature, differ from one station to another.

Sunshine Hours, Evaporation and Solar Radiation: Historical data on sunshine hours and mean evaporation rates were not available at the time of writing. Kota Kinabalu station is the only station with the solar radiation data.

Flood and Drought Prone Areas: Information (recent and historical data) of the period of flood occurrence within a year would greatly help in the development of a flood mitigation measure called the ‘early warning system’. Under this system, people living in flood-prone areas can be warned of the problem in advance and appropriate measures can be taken at an early stage. Recent and historical data on drought-prone areas are also needed in the management of drought-related problems.

Haze: The recent and historical data on the Air Pollution Index (API) were not available at the time of writing.

3.5  ICZM Issues Arising

It is today recognised that climate changes due to anthropogenic activities could result in sea-level rise in coastal area, depletion of ozone layer, etc. At present, these issues are dealt with through international research and other activities and are considered beyond the scope of the Sabah ICZM project. Consequently, in the context of the Sabah climate-related ICZM issues, only effects of climate conditions are highlighted and discussed.

3.5.1  Issues related to geographical distribution (spatial)

Sandakan, in particular, registered a relatively high rainfall reading towards the end of the year (Figure 8 and Table 9), reaching the maximum average of the monthly mean rainfall in December with a record of approximately 0.5 m (517.9 mm) between 1990 and 1997. This occurrence coincides with the Northeast Monsoon that usually prevails between November and March. The 0.5 m rainfall during the period suggests that the threat of flooding would be an issue especially in low-lying areas in Sandakan.

The Kinabatangan River, which is the main source of water of the Sandakan residency, faces the problem of bank erosion and siltation. While heavy rainfall contributes to the problems to a certain extent, human activities such as forest clearing share a greater deal of responsibilities in this matter. Forest clearing activities expose soil to adverse environmental conditions. Erosion and siltation are two major issues that need attention as the effects of the former and latter could impede navigation in rivers, and also aggravate problems such as flooding.

3.5.2  Issues related to seasonal variability (temporal)

Flood and drought related problems are the main concerns when the monsoons prevail in Sabah each year. When the monsoons prevail and at the same time bringing a substantial amount of rainfall to the region, low-lying areas (e.g. Kinabatangan, Beaufort, etc) experience the problem of flooding.

On the other hand, when the supply of rainfall is scarce, problems such as water shortage, forest fires, etc could arise, bringing much discomfort and inconvenience to the people. The problem of forest fires does not only affect people, but also potentially leads to the loss of biodiversity of fauna and flora, and displacement of fauna in the areas affected.

3.5.3  Issues related to annual variability (trend)

At the annual level, flooding and drought problems are issues that require attention due to the high annual variability of rainfall distribution in Sabah. Events such as El Niņo38 and La Niņa39 bring extreme weather conditions to the region and could potentially lead to drought and flooding problems, respectively. Although these events do not occur on a yearly basis, the problems that arise from these need attention in the ICZM project.

Previous ChapterContentsNext


37Relative humidity data for Kudat were not available at the time of writing.

38El Niņo is a disruption of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe. Among these consequences are increased rainfall across the southern tier of the US and in Peru, and drought in the west Pacific (including Malaysia). Source: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration (http://www.noaa.gov/).

39La Niņa is characterised by unusually cold ocean temperatures in the equatorial Pacific, as compared to El Niņo, which is characterised by unusually warm ocean temperatures in the Equatorial Pacific. Source: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration (http://www.noaa.gov/).