Climate and Average Weather Year Round in Siem Pang Cambodia

In Siem Pang, the wet season is oppressive and overcast, the dry season is muggy and partly cloudy, and it is hot year round. Over the course of the year, the temperature typically varies from 67°F to 96°F and is rarely below 61°F or above 102°F.

Based on the beach/pool score, the best time of year to visit Siem Pang for hot-weather activities is from mid November to early March.

The hot season lasts for 2.0 months, from March 11 to May 10, with an average daily high temperature above 94°F. The hottest month of the year in Siem Pang is April, with an average high of 96°F and low of 78°F.

The cool season lasts for 2.0 months, from November 28 to January 28, with an average daily high temperature below 89°F. The coldest month of the year in Siem Pang is January, with an average low of 67°F and high of 88°F.

In Siem Pang, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.

The clearer part of the year in Siem Pang begins around November 3 and lasts for 5.0 months, ending around April 2.

The clearest month of the year in Siem Pang is February, during which on average the sky is clear, mostly clear, or partly cloudy 55% of the time.

The cloudier part of the year begins around April 2 and lasts for 7.0 months, ending around November 3.

The cloudiest month of the year in Siem Pang is August, during which on average the sky is overcast or mostly cloudy 93% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Siem Pang varies very significantly throughout the year.

The wetter season lasts 5.5 months, from May 3 to October 20, with a greater than 28% chance of a given day being a wet day. The month with the most wet days in Siem Pang is August, with an average of 16.3 days with at least 0.04 inches of precipitation.

The drier season lasts 6.5 months, from October 20 to May 3. The month with the fewest wet days in Siem Pang is February, with an average of 0.7 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Siem Pang is August, with an average of 16.3 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 54% on September 7.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Siem Pang experiences extreme seasonal variation in monthly rainfall.

The rainy period of the year lasts for 8.8 months, from March 15 to December 9, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Siem Pang is August, with an average rainfall of 7.8 inches.

The rainless period of the year lasts for 3.2 months, from December 9 to March 15. The month with the least rain in Siem Pang is January, with an average rainfall of 0.1 inches.

The length of the day in Siem Pang varies over the course of the year. In 2024, the shortest day is December 21, with 11 hours, 18 minutes of daylight; the longest day is June 21, with 12 hours, 58 minutes of daylight.

The earliest sunrise is at 5:25 AM on June 2, and the latest sunrise is 58 minutes later at 6:22 AM on January 24. The earliest sunset is at 5:22 PM on November 21, and the latest sunset is 1 hour, 4 minutes later at 6:27 PM on July 8.

Daylight saving time (DST) is not observed in Siem Pang during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Siem Pang experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 10.0 months, from February 11 to December 10, during which time the comfort level is muggy, oppressive, or miserable at least 56% of the time.

The month with the fewest muggy days in Siem Pang is January, with 13.4 days that are muggy or worse.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Siem Pang does not vary significantly over the course of the year, remaining within 0.4 miles per hour of 2.3 miles per hour throughout.

The predominant average hourly wind direction in Siem Pang varies throughout the year.

The wind is most often from the south for 2.2 months, from March 30 to June 7, with a peak percentage of 50% on May 21. The wind is most often from the west for 3.9 months, from June 7 to October 4, with a peak percentage of 60% on August 9. The wind is most often from the east for 5.8 months, from October 4 to March 30, with a peak percentage of 61% on January 1.

To characterize how pleasant the weather is in Siem Pang throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Siem Pang for general outdoor tourist activities is from early December to early February, with a peak score in the first week of January.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Siem Pang for hot-weather activities is from mid November to early March, with a peak score in the second week of February.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures in Siem Pang are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences some seasonal variation over the course of the year.

The brighter period of the year lasts for 2.5 months, from January 29 to April 13, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest month of the year in Siem Pang is March, with an average of 6.2 kWh.

The darker period of the year lasts for 3.9 months, from May 31 to September 26, with an average daily incident shortwave energy per square meter below 4.5 kWh. The darkest month of the year in Siem Pang is August, with an average of 4.1 kWh.

For the purposes of this report, the geographical coordinates of Siem Pang are 14.117 deg latitude, 106.388 deg longitude, and 233 ft elevation.

The topography within 2 miles of Siem Pang contains only modest variations in elevation, with a maximum elevation change of 125 feet and an average elevation above sea level of 238 feet. Within 10 miles contains only modest variations in elevation (522 feet). Within 50 miles contains significant variations in elevation (4,751 feet).

The area within 2 miles of Siem Pang is covered by trees (81%) and cropland (11%), within 10 miles by trees (87%), and within 50 miles by trees (89%).