This report describes the typical weather at the St. Augustine Airport (St. Augustine, Florida, United States) weather station over the course of an average October. It is based on the historical records from 1997 to 2012. Earlier records are either unavailable or unreliable.
St. Augustine, Florida 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 (46%), forests (39%), croplands (9%), and lakes and rivers (5%).
The month of October is characterized by falling daily high temperatures, with daily highs decreasing from 83°F to 76°F over the course of the month, exceeding 87°F or dropping below 69°F only one day in ten.
Over the course of October, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 51 minutes, implying an average day-over-day decrease of 1.7 minutes.
The shortest day of the month is October 31 with 11:00 hours of daylight; the longest day is October 1 with 11:51 hours of daylight.
The earliest sunrise is at 7:19am on October 1; the latest sunset is at 7:10pm on October 1; the latest sunrise is at 7:38am on October 30; the earliest sunset is at 6:39pm on October 31.
Daylight savings time is observed in 2012 but it neither starts nor ends in October, so the entire month is in daylight time.
The median cloud cover ranges from 19% (mostly clear) to 26% (mostly clear). The trend is for the sky to be clearing with the median cloud cover decreasing by 5% from the start to the end of the month.
On October 16, a representative day, the sky is clear or mostly clear 56% of the time, partly cloudy 10% of the time, and mostly cloudy or overcast 30% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around October 1, occurring in 19% of days. Precipitation is least likely around October 29, occurring in 11% of days.
Throughout October, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 53% of those days with precipitation. They are most likely around October 1, when it is observed during 12% of all days.
Light rain is the most severe precipitation observed during 29% of those days with precipitation. It is most likely around October 13, when it is observed during 4% of all days.
Moderate rain is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around October 3, when it is observed during 2% of all days.
Either snow is exceptionally unlikely to fall at this location in October or this station does not reliably report precipitation types.
The relative humidity typically ranges from 57% (mildly humid) to 91% (very humid) over the course of a typical October, rarely dropping below 38% (comfortable) and reaching as high as 100% (very humid).
The air is driest around October 24, at which time the relative humidity drops below 66% (mildly humid) three days out of four; it is most humid around October 1, rising above 87% (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 October, the dew point typically varies from 54°F (very comfortable) to 71°F (very muggy) and is rarely below 40°F (dry) or above 76°F (very muggy).
Over the course of October typical wind speeds vary from 0 mph to 14 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around October 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around October 21, at which time the average daily maximum wind speed is 14 mph (moderate breeze).