This report describes the typical weather at the Cozumel International Airport (Cozumel, Mexico) weather station over the course of an average July. It is based on the historical records from 1991 to 2012. Earlier records are either unavailable or unreliable.
Cozumel has a tropical monsoon climate with short dry season. The area within 25 mi of this station is covered by oceans and seas (69%) and forests (30%).
The month of July is characterized by essentially constant daily high temperatures, with daily highs around 90°F throughout the month, exceeding 93°F or dropping below 85°F only one day in ten.
Over the course of July, the length of the day is essentially constant. The shortest day of the month is July 31 with 13:04 hours of daylight; the longest day is July 2 with 13:22 hours of daylight.
The earliest sunrise is at 6:11am on July 1; the latest sunset is at 7:33pm on July 2; the latest sunrise is at 6:22am on July 29; the earliest sunset is at 7:26pm on July 31.
Daylight saving time is observed in 2012 but it neither starts nor ends in July, so the entire month is in daylight time.
The median cloud cover ranges from 61% (partly cloudy) to 68% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 6% from the start to the end of the month.
On July 16, a representative day, the sky is clear or mostly clear 5% of the time, partly cloudy 18% of the time, and mostly cloudy or overcast 22% of the time.
The average probability that some form of precipitation will be observed in a given day is 26%, with little variation over the course of the month.
Throughout July, the most common forms of precipitation are light rain, moderate rain, and thunderstorms.
Light rain is the most severe precipitation observed during 38% of those days with precipitation. It is most likely around July 31, when it is observed during 11% of all days.
Moderate rain is the most severe precipitation observed during 30% of those days with precipitation. It is most likely around July 1, when it is observed during 9% of all days.
Thunderstorms are the most severe precipitation observed during 21% of those days with precipitation. They are most likely around July 5, when it is observed during 6% of all days.
Either snow is exceptionally unlikely to fall at this location in July or this station does not reliably report precipitation types.
The relative humidity typically ranges from 62% (mildly humid) to 92% (very humid) over the course of a typical July, rarely dropping below 55% (mildly humid) and reaching as high as 100% (very humid).
The air is driest around July 28, at which time the relative humidity drops below 65% (mildly humid) three days out of four; it is most humid around July 27, 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 July, the dew point typically varies from 73°F (very muggy) to 78°F (oppressive) and is rarely below 71°F (very muggy) or above 80°F (very oppressive).
Over the course of July 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 7 mph (light breeze) occurs around July 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around July 31, at which time the average daily maximum wind speed is 13 mph (moderate breeze).