This report describes the typical weather at the Scholes International Airport at Galveston (Galveston, Texas, United States) weather station over the course of an average December. It is based on the historical records from 1992 to 2012. Earlier records are either unavailable or unreliable.
Galveston, 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 oceans and seas (76%) and croplands (21%).
The month of December is characterized by falling daily high temperatures, with daily highs decreasing from 66°F to 61°F over the course of the month, exceeding 76°F or dropping below 50°F only one day in ten.
Over the course of December, the length of the day is essentially constant. The shortest day of the month is December 27 with 10:16 hours of daylight; the longest day is December 1 with 10:25 hours of daylight.
The earliest sunrise is at 6:56am on December 1; the latest sunset is at 5:32pm on December 31; the latest sunrise is at 7:13am on December 30; the earliest sunset is at 5:20pm on December 3.
Daylight saving time is observed in 2012 but it neither starts nor ends in December, so the entire month is in standard time.
The median cloud cover ranges from 41% (partly cloudy) to 59% (partly cloudy). The trend is for the sky to be becoming rapidly cloudier with the median cloud cover increasing by 18% from the start to the end of the month.
On December 1, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 51% of the time, and overcast or mostly cloudy 41% of the time.
On December 31, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 50% of the time, and clear or mostly clear 43% of the time.
The average probability that some form of precipitation will be observed in a given day is 34%, with little variation over the course of the month.
Throughout December, the most common forms of precipitation are light rain, moderate rain, thunderstorms, and heavy rain.
Light rain is the most severe precipitation observed during 43% of those days with precipitation. It is most likely around December 26, when it is observed during 16% of all days.
Moderate rain is the most severe precipitation observed during 19% of those days with precipitation. It is most likely around December 31, when it is observed during 7% of all days.
Thunderstorms are the most severe precipitation observed during 17% of those days with precipitation. They are most likely around December 1, when it is observed during 7% of all days.
Heavy rain is the most severe precipitation observed during 16% of those days with precipitation. It is most likely around December 8, when it is observed during 6% of all days.
Either snow is exceptionally unlikely to fall at this location in December or this station does not reliably report precipitation types.
The relative humidity typically ranges from 62% (mildly humid) to 91% (very humid) over the course of a typical December, rarely dropping below 38% (comfortable) and reaching as high as 100% (very humid).
The air is driest around December 1, at which time the relative humidity drops below 75% (humid) three days out of four; it is most humid around December 31, rising above 86% (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 December, the dew point typically varies from 42°F (dry) to 58°F (comfortable) and is rarely below 28°F (dry) or above 70°F (muggy).
The time of the month between December 1 and December 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of December typical wind speeds vary from 5 mph to 18 mph (light breeze to fresh breeze), rarely exceeding 26 mph (strong breeze).
The highest average wind speed of 12 mph (moderate breeze) occurs around December 15, at which time the average daily maximum wind speed is 18 mph (moderate breeze).
The lowest average wind speed of 12 mph (gentle breeze) occurs around December 26, at which time the average daily maximum wind speed is 18 mph (moderate breeze).