Average Weather in San Leon Texas, United States
In San Leon, the summers are long, hot, and oppressive; the winters are short, cool, and windy; and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 48°F to 91°F and is rarely below 36°F or above 94°F.
Based on the tourism score, the best times of year to visit San Leon for warm-weather activities are from late March to mid May and from early October to early November.
The hot season lasts for 4.0 months, from May 26 to September 26, with an average daily high temperature above 85°F. The hottest day of the year is August 5, with an average high of 91°F and low of 79°F.
The cool season lasts for 2.9 months, from December 2 to February 27, with an average daily high temperature below 67°F. The coldest day of the year is January 6, with an average low of 48°F and high of 61°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 San Leon, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in San Leon begins around September 16 and lasts for 2.7 months, ending around December 7. On October 26, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 69% of the time, and overcast or mostly cloudy 31% of the time.
The cloudier part of the year begins around December 7 and lasts for 9.3 months, ending around September 16. On August 20, the cloudiest day of the year, the sky is overcast or mostly cloudy 52% of the time, and clear, mostly clear, or partly cloudy 48% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in San Leon varies throughout the year.
The wetter season lasts 4.0 months, from May 22 to September 23, with a greater than 30% chance of a given day being a wet day. The chance of a wet day peaks at 40% on September 4.
The drier season lasts 8.0 months, from September 23 to May 22. The smallest chance of a wet day is 21% on April 1.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 40% on September 4.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. San Leon experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in San Leon. The most rain falls during the 31 days centered around September 7, with an average total accumulation of 4.9 inches.
The least rain falls around March 4, with an average total accumulation of 3.0 inches.
Average Monthly Rainfall
The length of the day in San Leon varies significantly over the course of the year. In 2018, the shortest day is December 21, with 10 hours, 15 minutes of daylight; the longest day is June 21, with 14 hours, 2 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:19 AM on June 10, and the latest sunrise is 1 hour, 15 minutes later at 7:34 AM on November 3. The earliest sunset is at 5:20 PM on December 1, and the latest sunset is 3 hours, 3 minutes later at 8:23 PM on June 30.
Daylight saving time (DST) is observed in San Leon during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
San Leon experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 7.6 months, from March 28 to November 15, during which time the comfort level is muggy, oppressive, or miserable at least 28% of the time. The muggiest day of the year is July 21, with muggy conditions 99% of the time.
The least muggy day of the year is January 29, with muggy conditions 5% of the time.
Humidity Comfort Levels
The average hourly wind speed in San Leon experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 8.1 months, from October 7 to June 9, with average wind speeds of more than 9.7 miles per hour. The windiest day of the year is April 11, with an average hourly wind speed of 11.5 miles per hour.
The calmer time of year lasts for 3.9 months, from June 9 to October 7. The calmest day of the year is August 15, with an average hourly wind speed of 7.8 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in San Leon varies throughout the year.
The wind is most often from the south for 7.1 months, from February 5 to September 7 and for 3.3 weeks, from November 10 to December 3, with a peak percentage of 72% on June 27. The wind is most often from the east for 2.1 months, from September 7 to November 10, with a peak percentage of 43% on September 20. The wind is most often from the north for 2.1 months, from December 3 to February 5, with a peak percentage of 36% on January 1.
San Leon 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 water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 4.0 months, from June 1 to October 2, with an average temperature above 80°F. The day of the year with the warmest water is August 17, with an average temperature of 86°F.
The time of year with cooler water lasts for 3.3 months, from December 11 to March 19, with an average temperature below 64°F. The day of the year with the coolest water is January 29, with an average temperature of 59°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in San Leon throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit San Leon for general outdoor tourist activities are from late March to mid May and from early October to early November, with a peak score in the last week of April.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit San Leon for hot-weather activities are from early May to mid June and from mid to late September, with a peak score in the third week of May.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
While it does not do so every year, freezing temperatures are seen in San Leon over some winters. The day least likely to be in the growing season is January 16, with a 55% chance.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in San Leon should appear around January 16, only rarely appearing before January 10 or after January 28.
Growing Degree Days
The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 2.9 months, from April 5 to July 3, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is June 3, with an average of 6.6 kWh.
The darker period of the year lasts for 2.6 months, from November 15 to February 2, with an average daily incident shortwave energy per square meter below 3.7 kWh. The darkest day of the year is December 24, with an average of 3.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of San Leon are 29.483 deg latitude, -94.922 deg longitude, and 0 ft elevation.
The topography within 2 miles of San Leon is essentially flat, with a maximum elevation change of 13 feet and an average elevation above sea level of 2 foot. Within 10 miles is also essentially flat (33 feet). Within 50 miles is essentially flat (128 feet).
The area within 2 miles of San Leon is covered by water (73%), within 10 miles by water (61%) and artificial surfaces (19%), and within 50 miles by water (39%) and cropland (24%).
This report illustrates the typical weather in San Leon, 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 Leon.
For each station, the records are corrected for the elevation difference between that station and San Leon 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 Leon is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between San Leon and a given station.
The stations contributing to this reconstruction are: Scholes Field (52%, 24 kilometers, south); Ellington Field (42%, 28 kilometers, northwest); and Beaumont Municipal Airport (7%, 95 kilometers, northeast).
Time zones for aiports and weather stations are provided by AskGeo.com .