This report describes the typical weather at the Tocumen International Airport (Panama City) weather station over the course of an average September. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Panama City has a tropical monsoon climate with short dry season. The area within 25 mi of this station is covered by oceans and seas (37%), forests (33%), and croplands (25%).
The month of September is characterized by essentially constant daily high temperatures, with daily highs around 86°F throughout the month, exceeding 91°F or dropping below 82°F only one day in ten.
Over the course of September, the length of the day is essentially constant. The shortest day of the month is September 29 with 12:03 hours of daylight; the longest day is September 1 with 12:17 hours of daylight.
The earliest sunrise is at 6:06am on September 26; the latest sunset is at 6:26pm on September 1; the latest sunrise is at 6:09am on September 1; the earliest sunset is at 6:09pm on September 30.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover is 66% (partly cloudy) and does not vary substantially over the course of the month.
On September 15, a representative day, the sky is clear or mostly clear 20% of the time, partly cloudy 38% of the time, and mostly cloudy or overcast 36% of the time.
The average probability that some form of precipitation will be observed in a given day is 83%, with little variation over the course of the month.
Throughout September, the most common forms of precipitation are thunderstorms and moderate rain.
Thunderstorms are the most severe precipitation observed during 79% of those days with precipitation. They are most likely around September 1, when it is observed during 66% of all days.
Moderate rain is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around September 30, when it is observed during 12% of all days.
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 69% (mildly humid) to 98% (very humid) over the course of a typical September, rarely dropping below 60% (mildly humid) and reaching as high as 100% (very humid).
The air is driest around September 1, at which time the relative humidity drops below 74% (humid) three days out of four; it is most humid around September 23, rising above 99% (very humid) three days out of four.
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 72°F (very muggy) to 77°F (oppressive) and is rarely below 70°F (muggy) or above 79°F (oppressive).
Over the course of September typical wind speeds vary from 0 mph to 11 mph (calm to gentle breeze), rarely exceeding 15 mph (moderate breeze).
The highest average wind speed of 3 mph (light air) occurs around September 21, at which time the average daily maximum wind speed is 11 mph (gentle breeze).
The lowest average wind speed of 3 mph (light air) occurs around September 14, at which time the average daily maximum wind speed is 11 mph (gentle breeze).