Average Weather in May in San Antonio Puerto Rico
Daily high temperatures are around 87°F, rarely falling below 83°F or exceeding 91°F.
Daily low temperatures increase by 2°F, from 74°F to 76°F, rarely falling below 72°F or exceeding 78°F.
For reference, on August 5, the hottest day of the year, temperatures in San Antonio typically range from 77°F to 89°F, while on January 25, the coldest day of the year, they range from 70°F to 83°F.
Average High and Low Temperature in May
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on May. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in May
The month of May in San Antonio experiences very rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 47% to 73%. The highest chance of overcast or mostly cloudy conditions is 73% on May 30.
The clearest day of the month is May 1, with clear, mostly clear, or partly cloudy conditions 53% of the time.
For reference, on May 30, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 73%, while on January 11, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 82%.
Cloud Cover Categories in May
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In San Antonio, the chance of a wet day over the course of May is gradually increasing, starting the month at 40% and ending it at 43%.
For reference, the year's highest daily chance of a wet day is 51% on September 27, and its lowest chance is 20% on January 9.
Probability of Precipitation in May
The average sliding 31-day rainfall during May in San Antonio is gradually increasing, starting the month at 3.2 inches, when it rarely exceeds 6.7 inches or falls below 0.7 inches, and ending the month at 3.6 inches, when it rarely exceeds 7.4 inches or falls below 1.0 inches.
The highest average 31-day accumulation is 4.0 inches on May 20.
Average Monthly Rainfall in May
Over the course of May in San Antonio, the length of the day is gradually increasing. From the start to the end of the month, the length of the day increases by 21 minutes, implying an average daily increase of 41 seconds, and weekly increase of 4 minutes, 49 seconds.
The shortest day of the month is May 1, with 12 hours, 49 minutes of daylight and the longest day is May 31, with 13 hours, 10 minutes of daylight.
Hours of Daylight and Twilight in May
The latest sunrise of the month in San Antonio is 5:57 AM on May 1 and the earliest sunrise is 10 minutes earlier at 5:48 AM on May 31.
The earliest sunset is 6:46 PM on May 1 and the latest sunset is 11 minutes later at 6:57 PM on May 31.
Daylight saving time is not observed in San Antonio during 2021.
For reference, on June 21, the longest day of the year, the Sun rises at 5:49 AM and sets 13 hours, 14 minutes later, at 7:04 PM, while on December 21, the shortest day of the year, it rises at 6:52 AM and sets 11 hours, 1 minute later, at 5:54 PM.
Sunrise & Sunset with Twilight in May
The figure below presents a compact representation of key lunar data for May 2021. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in May
The chance that a given day will be muggy in San Antonio is gradually increasing during May, rising from 97% to 100% over the course of the month.
For reference, on June 1, the muggiest day of the year, there are muggy conditions 100% of the time, while on March 6, the least muggy day of the year, there are muggy conditions 79% of the time.
Humidity Comfort Levels in May
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in San Antonio is essentially constant during May, remaining within 0.1 miles per hour of 10.4 miles per hour throughout.
For reference, on July 14, the windiest day of the year, the daily average wind speed is 12.3 miles per hour, while on October 10, the calmest day of the year, the daily average wind speed is 9.1 miles per hour.
The lowest daily average wind speed during May is 10.3 miles per hour on May 21.
Average Wind Speed in May
The hourly average wind direction in San Antonio throughout May is predominantly from the east, with a peak proportion of 90% on May 31.
Wind Direction in May
San Antonio is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in San Antonio is essentially constant during May, remaining within 1°F of 81°F throughout.
Average Water Temperature in May
Temperatures in San Antonio are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season in May
The average accumulated growing degree days in San Antonio are very rapidly increasing during May, increasing by 904°F, from 3,254°F to 4,158°F, over the course of the month.
Growing Degree Days in May
The average daily incident shortwave solar energy in San Antonio is decreasing during May, falling by 1.1 kWh, from 6.7 kWh to 5.6 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in May
For the purposes of this report, the geographical coordinates of San Antonio are 18.449 deg latitude, -66.303 deg longitude, and 23 ft elevation.
The topography within 2 miles of San Antonio contains only modest variations in elevation, with a maximum elevation change of 331 feet and an average elevation above sea level of 90 feet. Within 10 miles contains only modest variations in elevation (1,378 feet). Within 50 miles contains very significant variations in elevation (4,390 feet).
The area within 2 miles of San Antonio is covered by trees (33%), cropland (29%), grassland (20%), and shrubs (15%), within 10 miles by water (44%) and trees (23%), and within 50 miles by water (69%) and trees (16%).
This report illustrates the typical weather in San Antonio, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in San Antonio.
For each station, the records are corrected for the elevation difference between that station and San Antonio according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at San Antonio is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between San Antonio and a given station.
The stations contributing to this reconstruction are: Luis Muñoz Marín International Airport (62%, 31 kilometers, east); Mercedita Airport (25%, 56 kilometers, southwest); and Rafael Hernandez Airport (13%, 87 kilometers, west).
Time zones for airports and weather stations are provided by AskGeo.com .