This report describes the typical weather at the Yangon International Airport (Yangon (Rangoon), Myanmar (Burma)) weather station over the course of an average September. It is based on the historical records from 2000 to 2012. Earlier records are either unavailable or unreliable.

Yangon (Rangoon) has a tropical monsoon climate with short dry season. The area within 25 mi of this station is covered by croplands (85%), oceans and seas (5%), forests (3%), built-up areas (3%), and lakes and rivers (2%).

The month of September is characterized by essentially constant daily high temperatures, with daily highs around 87°F throughout the month, exceeding 92°F or dropping below 82°F only one day in ten.

Daily High and Low Temperature in September

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The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Fraction of Time Spent in Various Temperature Bands in September

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The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).

Over the course of September, the length of the day is essentially constant. The shortest day of the month is September 30 with 11:60 hours of daylight; the longest day is September 1 with 12:27 hours of daylight.

Daily Hours of Daylight and Twilight in September

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The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.

The earliest sunrise is at 5:52am on September 2; the latest sunset is at 6:19pm on September 1; the latest sunrise is at 5:55am on September 30; the earliest sunset is at 5:55pm on September 30.

Daylight savings time (DST) is not observed in 2012.

Daily Sunrise & Sunset with Twilight in September

The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.

The median cloud cover ranges from 78% (partly cloudy) to 93% (mostly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 14% from the start to the end of the month.

Median Cloud Cover in September

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The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).

On September 30, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 36% of the time, and overcast or mostly cloudy 49% of the time.

On September 1, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 86% of the time, and clear or mostly clear 2% of the time.

Cloud Cover Types in September

The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around September 1, occurring in 89% of days. Precipitation is least likely around September 30, occurring in 74% of days.

Probability of Precipitation at Some Point in the Day in September

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The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.

Throughout September, the most common forms of precipitation are thunderstorms, moderate rain, and light rain.

Thunderstorms are the most severe precipitation observed during 45% of those days with precipitation. They are most likely around September 19, when it is observed during 39% of all days.

Moderate rain is the most severe precipitation observed during 27% of those days with precipitation. It is most likely around September 1, when it is observed during 29% of all days.

Light rain is the most severe precipitation observed during 14% of those days with precipitation. It is most likely around September 3, when it is observed during 13% of all days.

Types of Precipitation Throughout September

Relative frequency of various types of precipitation over the course of a typical September.

Either snow is exceptionally unlikely to fall at this location in September or this station does not reliably report precipitation types.

The relative humidity typically ranges from 70% (mildly humid) to 99% (very humid) over the course of a typical September, rarely dropping below 59% (mildly humid) and reaching as high as 100% (very humid).

The air is driest around September 30, at which time the relative humidity drops below 75% (humid) three days out of four; it is most humid around September 1, rising above 100% (very humid) three days out of four.

Relative Humidity in September

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The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).

Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.

Over the course of a typical September, the dew point typically varies from 75°F (very muggy) to 80°F (very oppressive) and is rarely below 73°F (very muggy) or above 81°F (very oppressive).

Dew Point in September

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The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Over the course of September typical wind speeds vary from 0 mph to 9 mph (calm to gentle breeze), rarely exceeding 12 mph (gentle breeze).

The highest average wind speed of 4 mph (light breeze) occurs around September 6, at which time the average daily maximum wind speed is 9 mph (gentle breeze).

The lowest average wind speed of 4 mph (light breeze) occurs around September 30, at which time the average daily maximum wind speed is 8 mph (gentle breeze).

Wind Speed in September

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The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind Directions in September

The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.

Fraction of Time Spent with Various Wind Directions in September

The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.