This report describes the typical weather at the Tyler Pounds Regional Airport (Tyler, Texas, United States) 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.
Tyler, Texas has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by croplands (60%), forests (36%), and lakes and rivers (3%).
The month of September is characterized by rapidly falling daily high temperatures, with daily highs decreasing from 92°F to 83°F over the course of the month, exceeding 98°F or dropping below 73°F only one day in ten.
Over the course of September, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 57 minutes, implying an average day-over-day decrease of 1.9 minutes.
The shortest day of the month is September 30 with 11:51 hours of daylight; the longest day is September 1 with 12:48 hours of daylight.
The earliest sunrise is at 6:57am on September 1; the latest sunset is at 7:45pm on September 1; the latest sunrise is at 7:16am on September 30; the earliest sunset is at 7:07pm on September 30.
Daylight savings time is observed in 2012 but it neither starts nor ends in September, so the entire month is in daylight time.
The median cloud cover is 24% (mostly clear) and does not vary substantially over the course of the month.
On September 15, a representative day, the sky is clear or mostly clear 47% of the time, partly cloudy 13% of the time, and mostly cloudy or overcast 26% of the time.
The average probability that some form of precipitation will be observed in a given day is 24%, with little variation over the course of the month.
Throughout September, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 44% of those days with precipitation. They are most likely around September 1, when it is observed during 12% of all days.
Light rain is the most severe precipitation observed during 30% of those days with precipitation. It is most likely around September 30, when it is observed during 8% of all days.
Moderate rain is the most severe precipitation observed during 18% of those days with precipitation. It is most likely around September 29, when it is observed during 5% 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 44% (comfortable) to 93% (very humid) over the course of a typical September, rarely dropping below 26% (dry) and reaching as high as 100% (very humid).
The air is driest around September 26, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around September 16, rising above 90% (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 53°F (very comfortable) to 71°F (very muggy) and is rarely below 40°F (dry) or above 75°F (very muggy).
Over the course of September typical wind speeds vary from 0 mph to 12 mph (calm to moderate breeze), rarely exceeding 18 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around September 28, at which time the average daily maximum wind speed is 12 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around September 1, at which time the average daily maximum wind speed is 12 mph (gentle breeze).