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Fall Weather in San Marcos Mexico

Daily high temperatures decrease by 16°F, from 91°F to 74°F, rarely falling below 65°F or exceeding 95°F.

Daily low temperatures decrease by 21°F, from 71°F to 49°F, rarely falling below 41°F or exceeding 74°F.

For reference, on June 4, the hottest day of the year, temperatures in San Marcos typically range from 72°F to 96°F, while on January 7, the coldest day of the year, they range from 45°F to 70°F.

Average High and Low Temperature in the Fall in San Marcos

Average High and Low Temperature in the Fall in San MarcosSepOctNov40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FSummerWinterSep 191°FSep 191°F71°F71°FNov 3074°FNov 3074°F49°F49°FOct 187°FOct 187°F66°F66°FNov 181°FNov 181°F57°F57°FNowNow
The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average fall temperatures. 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 the Fall in San Marcos

Average Hourly Temperature in the Fall in San MarcosSepOctNov12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMSummerWinterNowNowcoldcoolcoolcomfortablewarmwarmhot
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Tses, Namibia (8,809 miles away) is the far-away foreign place with temperatures most similar to San Marcos (view comparison).

Compare San Marcos to another city:

Clouds

The fall in San Marcos experiences very rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 53% to 37%. The highest chance of overcast or mostly cloudy conditions is 54% on September 6. The lowest chance of overcast or mostly cloudy conditions is 31% on November 11.

The clearest day of the fall is November 11, with clear, mostly clear, or partly cloudy conditions 69% of the time.

For reference, on September 6, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 54%, while on June 2, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 77%.

Cloud Cover Categories in the Fall in San Marcos

Cloud Cover Categories in the Fall in San MarcosSepOctNov0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%SummerWinterJun 277%Jun 277%Sep 646%Sep 646%Nov 3063%Nov 3063%Oct 156%Oct 156%Nov 167%Nov 167%NowNowclearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In San Marcos, the chance of a wet day over the course of the fall is very rapidly decreasing, starting the season at 24% and ending it at 5%.

For reference, the year's highest daily chance of a wet day is 26% on July 15, and its lowest chance is 2% on February 20.

Probability of Precipitation in the Fall in San Marcos

Probability of Precipitation in the Fall in San MarcosSepOctNov0%0%5%5%10%10%15%15%20%20%25%25%SummerWinterSep 725%Sep 725%Nov 305%Nov 305%Oct 116%Oct 116%Nov 16%Nov 16%NowNowrain
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during the fall in San Marcos is rapidly decreasing, starting the season at 1.8 inches, when it rarely exceeds 3.6 inches or falls below 0.3 inches, and ending the season at 0.3 inches, when it rarely exceeds 0.8 inches or falls below -0.0 inches.

The highest average 31-day accumulation is 1.8 inches on September 3.

Average Monthly Rainfall in the Fall in San Marcos

Average Monthly Rainfall in the Fall in San MarcosSepOctNov0.0 in0.0 in0.5 in0.5 in1.0 in1.0 in1.5 in1.5 in2.0 in2.0 in2.5 in2.5 in3.0 in3.0 in3.5 in3.5 in4.0 in4.0 inSummerWinterSep 31.8 inSep 31.8 inNov 300.3 inNov 300.3 inOct 11.2 inOct 11.2 inNov 10.5 inNov 10.5 inNowNow
The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Sun

Over the course of the fall in San Marcos, the length of the day is rapidly decreasing. From the start to the end of the season, the length of the day decreases by 1 hour, 58 minutes, implying an average daily decrease of 1 minute, 19 seconds, and weekly decrease of 9 minutes, 13 seconds.

The shortest day of the fall is November 30, with 10 hours, 40 minutes of daylight and the longest day is September 1, with 12 hours, 38 minutes of daylight.

Hours of Daylight and Twilight in the Fall in San Marcos

Hours of Daylight and Twilight in the Fall in San MarcosSepOctNov0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hrSummerWinterSep 2212 hr, 7 minSep 2212 hr, 7 minnightnightdaydayNov 3010 hr, 40 minNov 3010 hr, 40 minNov 111 hr, 10 minNov 111 hr, 10 minNowNow
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The latest sunrise of the fall in San Marcos is 7:59 AM on October 30 and the earliest sunrise is 59 minutes earlier at 6:59 AM on October 31.

The latest sunset is 8:10 PM on September 1 and the earliest sunset is 2 hours, 10 minutes earlier at 6:00 PM on November 29.

Daylight saving time (DST) ends at 1:00 AM on October 31, 2021, shifting sunrise and sunset to be an hour earlier.

For reference, on June 21, the longest day of the year, the Sun rises at 7:01 AM and sets 13 hours, 45 minutes later, at 8:46 PM, while on December 21, the shortest day of the year, it rises at 7:34 AM and sets 10 hours, 32 minutes later, at 6:06 PM.

Sunrise & Sunset with Twilight and Daylight Saving Time in the Fall in San Marcos

Sunrise & Sunset with Twilight and Daylight Saving Time in the Fall in San MarcosSepOctNov2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMSummerWinter6:59 AM6:59 AMOct 316:11 PMOct 316:11 PM7:32 AM7:32 AMSep 18:10 PMSep 18:10 PM7:20 AM7:20 AMNov 296:00 PMNov 296:00 PM7:44 AM7:44 AMOct 17:38 PMOct 17:38 PMDSTOct 31DSTOct 31SolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day in the fall. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Moon

The figure below presents a compact representation of key lunar data for the fall of 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 the Fall in San Marcos

Moon Rise, Set & Phases in the Fall in San MarcosSepOctNov12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMSummerWinterAug 88:51 AMAug 88:51 AMAug 227:03 AMAug 227:03 AMSep 67:52 PMSep 67:52 PMSep 206:55 PMSep 206:55 PMOct 66:06 AMOct 66:06 AMOct 209:57 AMOct 209:57 AMNov 43:15 PMNov 43:15 PMNov 192:58 AMNov 192:58 AMDec 41:44 AMDec 41:44 AMDec 1810:36 PMDec 1810:36 PM9:05 PM9:05 PM8:16 PM8:16 PM7:31 AM7:31 AM7:06 AM7:06 AM8:19 PM8:19 PM8:03 PM8:03 PM8:12 AM8:12 AM7:53 AM7:53 AM8:03 PM8:03 PM7:07 PM7:07 PM7:51 AM7:51 AM6:42 AM6:42 AM6:15 PM6:15 PM5:46 PM5:46 PM7:25 AM7:25 AM6:32 PM6:32 PM5:46 PM5:46 PM8:02 AM8:02 AMNowNow
The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

Humidity

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in San Marcos is very rapidly decreasing during the fall, falling from 20% to 0% over the course of the season.

The highest chance of a muggy day during the fall is 21% on September 5.

For reference, on September 5, the muggiest day of the year, there are muggy conditions 21% of the time, while on December 12, the least muggy day of the year, there are muggy conditions 0% of the time.

Humidity Comfort Levels in the Fall in San Marcos

Humidity Comfort Levels in the Fall in San MarcosSepOctNov0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%SummerWinterSep 521%Sep 521%Nov 300%Nov 300%Oct 112%Oct 112%Nov 11%Nov 11%NowNowmuggymuggyhumidhumidcomfortablecomfortabledrydry
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

Wind

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in San Marcos is decreasing during the fall, decreasing from 7.9 miles per hour to 5.9 miles per hour over the course of the season.

For reference, on July 2, the windiest day of the year, the daily average wind speed is 8.3 miles per hour, while on December 3, the calmest day of the year, the daily average wind speed is 5.9 miles per hour.

Average Wind Speed in the Fall in San Marcos

Average Wind Speed in the Fall in San MarcosSepOctNov0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mphSummerWinterSep 17.9 mphSep 17.9 mphNov 305.9 mphNov 305.9 mphOct 17.0 mphOct 17.0 mphNov 16.2 mphNov 16.2 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The hourly average wind direction in San Marcos throughout the fall is predominantly from the east, with a peak proportion of 74% on September 1.

Wind Direction in the Fall in San Marcos

Wind Direction in the Fall in San MarcosSepOctNov0%100%20%80%40%60%60%40%80%20%100%0%SummerWinterNowNowwestsoutheastnorth
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Growing Season

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

While it does not do so every year, freezing temperatures are seen in San Marcos over some winters. The day least likely to be in the growing season is January 2, with a 78% chance.

Time Spent in Various Temperature Bands and the Growing Season in the Fall in San Marcos

Time Spent in Various Temperature Bands and the Growing Season in the Fall in San Marcosgrowing seasonSepOctNov0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%SummerWinter100%Sep 1100%Sep 196%Nov 3096%Nov 30100%Oct 1100%Oct 1100%Nov 1100%Nov 1Oct 7100%Oct 7100%NowNowcoldcoolcomfortablewarmhotvery coldsweltering
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days in San Marcos are very rapidly increasing during the fall, increasing by 1,937°F, from 5,738°F to 7,675°F, over the course of the season.

Growing Degree Days in the Fall in San Marcos

Growing Degree Days in the Fall in San MarcosSepOctNov5,500°F5,500°F6,000°F6,000°F6,500°F6,500°F7,000°F7,000°F7,500°F7,500°F8,000°F8,000°FSummerWinterSep 15,738°FSep 15,738°FNov 307,675°FNov 307,675°FOct 16,559°FOct 16,559°FNov 17,247°FNov 17,247°FNowNow
The average growing degree days accumulated over the course of the fall, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy in San Marcos is very rapidly decreasing during the fall, falling by 2.2 kWh, from 6.6 kWh to 4.3 kWh, over the course of the season.

Average Daily Incident Shortwave Solar Energy in the Fall in San Marcos

Average Daily Incident Shortwave Solar Energy in the Fall in San MarcosSepOctNov0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWhSummerWinterSep 16.6 kWhSep 16.6 kWhNov 304.3 kWhNov 304.3 kWhOct 15.9 kWhOct 15.9 kWhNov 15.1 kWhNov 15.1 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of San Marcos are 25.667 deg latitude, -103.009 deg longitude, and 3,625 ft elevation.

The topography within 2 miles of San Marcos is essentially flat, with a maximum elevation change of 36 feet and an average elevation above sea level of 3,615 feet. Within 10 miles is essentially flat (1,745 feet). Within 50 miles contains very significant variations in elevation (7,500 feet).

The area within 2 miles of San Marcos is covered by shrubs (90%), within 10 miles by shrubs (61%) and grassland (21%), and within 50 miles by shrubs (66%) and herbaceous vegetation (11%).

Data Sources

This report illustrates the typical weather in San Marcos, 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 is only a single weather station, Francisco Sarabia International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of San Marcos.

At a distance of 42 kilometers from San Marcos, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records.

The station records are corrected for the elevation difference between the station and San Marcos according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.