1. WeatherSpark.com
  2. Mexico
  3. Tamaulipas
  4. San Fernando

September Weather in San Fernando Mexico

Daily high temperatures decrease by 5°F, from 94°F to 89°F, rarely falling below 82°F or exceeding 99°F.

Daily low temperatures decrease by 5°F, from 73°F to 68°F, rarely falling below 58°F or exceeding 76°F.

For reference, on August 3, the hottest day of the year, temperatures in San Fernando typically range from 74°F to 96°F, while on January 5, the coldest day of the year, they range from 49°F to 73°F.

Average High and Low Temperature in September in San Fernando

Average High and Low Temperature in September in San FernandoSep11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303045°F45°F50°F50°F55°F55°F60°F60°F65°F65°F70°F70°F75°F75°F80°F80°F85°F85°F90°F90°F95°F95°F100°F100°F105°F105°FAugOctSep 194°FSep 194°F73°F73°FSep 3089°FSep 3089°F68°F68°FSep 1192°FSep 1192°F71°F71°FSep 2190°FSep 2190°F69°F69°F
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 temperatures for the quarter of the year centered on September. 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 September in San Fernando

Average Hourly Temperature in September in San FernandoSep11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMAugOctcoolcomfortablecomfortablewarmwarmhotsweltering
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.

Mount Isa, Australia (8,790 miles away) is the far-away foreign place with temperatures most similar to San Fernando (view comparison).

Map
Marker
© OpenStreetMap contributors

Compare San Fernando to another city:

Map

The month of September in San Fernando experiences decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 59% to 48%. The highest chance of overcast or mostly cloudy conditions is 60% on September 5.

The clearest day of the month is September 30, with clear, mostly clear, or partly cloudy conditions 52% of the time.

For reference, on August 23, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 60%, while on May 29, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 73%.

Cloud Cover Categories in September in San Fernando

Cloud Cover Categories in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%AugOctMay 2973%May 2973%Sep 141%Sep 141%Sep 3052%Sep 3052%Sep 1143%Sep 1143%Sep 2147%Sep 2147%clearmostly 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.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In San Fernando, the chance of a wet day over the course of September is decreasing, starting the month at 34% and ending it at 29%.

For reference, the year's highest daily chance of a wet day is 38% on September 13, and its lowest chance is 7% on December 9.

Probability of Precipitation in September in San Fernando

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 month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during September in San Fernando is decreasing, starting the month at 4.4 inches, when it rarely exceeds 8.9 inches or falls below 0.8 inches, and ending the month at 3.7 inches, when it rarely exceeds 8.1 inches or falls below 0.8 inches.

The highest average 31-day accumulation is 4.9 inches on September 14.

Average Monthly Rainfall in September in San Fernando

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 snowfall.

Over the course of September in San Fernando, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 41 minutes, implying an average daily decrease of 1 minute, 26 seconds, and weekly decrease of 9 minutes, 59 seconds.

The shortest day of the month is September 30, with 11 hours, 55 minutes of daylight and the longest day is September 1, with 12 hours, 37 minutes of daylight.

Hours of Daylight and Twilight in September in San Fernando

Hours of Daylight and Twilight in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hrAugOctSep 2212 hr, 8 minSep 2212 hr, 8 minnightnightdaydaySep 112 hr, 37 minSep 112 hr, 37 min
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 earliest sunrise of the month in San Fernando is 6:13 AM on September 1 and the latest sunrise is 11 minutes later at 6:24 AM on September 30.

The latest sunset is 6:50 PM on September 1 and the earliest sunset is 31 minutes earlier at 6:19 PM on September 30.

Daylight saving time is not observed in San Fernando during 2024.

For reference, on June 20, the longest day of the year, the Sun rises at 5:43 AM and sets 13 hours, 41 minutes later, at 7:24 PM, while on December 21, the shortest day of the year, it rises at 7:13 AM and sets 10 hours, 36 minutes later, at 5:48 PM.

Sunrise & Sunset with Twilight in September in San Fernando

Sunrise & Sunset with Twilight in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930302 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMAugOct6:13 AM6:13 AMSep 16:50 PMSep 16:50 PM6:24 AM6:24 AMSep 306:19 PMSep 306:19 PM6:17 AM6:17 AMSep 116:40 PMSep 116:40 PMSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of September. 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 figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in September in San Fernando

Solar Elevation and Azimuth in September in San FernandoSep11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMAugOct001010202020303040405050506070800001010202030303040405050606070
northeastsouthwest
Solar elevation and azimuth over the course of September 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for September 2024. 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 September in San Fernando

Moon Rise, Set & Phases in September in San FernandoSep11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303012 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMAugOctAug 45:14 AMAug 45:14 AMAug 1912:26 PMAug 1912:26 PMSep 27:56 PMSep 27:56 PMSep 178:35 PMSep 178:35 PMOct 212:50 PMOct 212:50 PMOct 175:27 AMOct 175:27 AM6:04 AM6:04 AM7:46 PM7:46 PM6:39 PM6:39 PM5:53 AM5:53 AM5:47 AM5:47 AM6:51 PM6:51 PM6:30 PM6:30 PM6:50 AM6:50 AM6:15 AM6:15 AM6:19 PM6:19 PM5:36 PM5:36 PM6:39 AM6:39 AM
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.
Sep 2024IlluminationMoonriseMoonsetMoonriseMeridian PassingDistance
1
2%4:54 AMENE6:21 PMWNW-11:40 AMS249,232 mi
2
0%5:47 AMENE6:51 PMW-12:21 PMS250,615 mi
3
0%6:39 AME7:20 PMW-1:01 PMS251,637 mi
4
3%7:29 AME7:48 PMW-1:40 PMS252,251 mi
5
7%8:19 AME8:16 PMW-2:18 PMS252,394 mi
6
12%9:10 AMESE8:45 PMWSW-2:57 PMS251,990 mi
7
20%10:02 AMESE9:17 PMWSW-3:39 PMS250,966 mi
8
28%10:55 AMESE9:52 PMWSW-4:24 PMS249,265 mi
9
37%11:52 AMESE10:33 PMWSW-5:12 PMS246,869 mi
10
48%12:50 PMESE11:21 PMWSW-6:05 PMS243,812 mi
11
50%1:49 PMESE--7:02 PMS240,203 mi
12
69%-12:15 AMWSW2:46 PMESE8:01 PMS236,236 mi
13
79%-1:16 AMWSW3:39 PMESE9:01 PMS232,190 mi
14
88%-2:22 AMWSW4:28 PMESE9:59 PMS228,408 mi
15
95%-3:29 AMWSW5:12 PMESE10:54 PMS225,253 mi
16
99%-4:37 AMWSW5:52 PMESE11:47 PMS223,057 mi
17
100%-5:44 AMW6:30 PME--
18
100%-6:50 AMW7:07 PME12:39 AMS222,056 mi
19
98%-7:56 AMW7:45 PMENE1:29 AMS222,349 mi
20
93%-9:03 AMWNW8:25 PMENE2:21 AMS223,878 mi
21
85%-10:11 AMWNW9:10 PMENE3:15 AMS226,444 mi
22
75%-11:19 AMWNW10:00 PMENE4:12 AMS229,749 mi
23
64%-12:25 PMWNW10:55 PMENE5:11 AMN233,451 mi
24
50%-1:26 PMWNW11:53 PMENE6:10 AMN237,226 mi
25
42%-2:20 PMWNW-7:08 AMN240,807 mi
26
32%12:53 AMENE3:07 PMWNW-8:02 AMN244,005 mi
27
23%1:52 AMENE3:48 PMWNW-8:52 AMS246,714 mi
28
15%2:49 AMENE4:23 PMWNW-9:38 AMS248,889 mi
29
8%3:43 AMENE4:54 PMWNW-10:21 AMS250,536 mi
30
4%4:35 AME5:23 PMW-11:01 AMS251,680 mi

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 Fernando is rapidly decreasing during September, falling from 97% to 78% over the course of the month.

For reference, on August 18, the muggiest day of the year, there are muggy conditions 98% of the time, while on January 17, the least muggy day of the year, there are muggy conditions 8% of the time.

Humidity Comfort Levels in September in San Fernando

Humidity Comfort Levels in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%AugOctSep 197%Sep 197%Sep 3078%Sep 3078%Sep 1193%Sep 1193%Sep 2186%Sep 2186%miserablemiserableoppressiveoppressivemuggymuggyhumidhumiddrydrycomfortablecomfortable
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.

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 Fernando is essentially constant during September, remaining within 0.2 miles per hour of 8.8 miles per hour throughout.

For reference, on April 25, the windiest day of the year, the daily average wind speed is 12.8 miles per hour, while on September 11, the calmest day of the year, the daily average wind speed is 8.6 miles per hour.

The lowest daily average wind speed during September is 8.6 miles per hour on September 16.

Average Wind Speed in September in San Fernando

Average Wind Speed in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mph16 mph16 mphAugOctSep 168.6 mphSep 168.6 mphSep 18.9 mphSep 18.9 mphSep 308.9 mphSep 308.9 mph
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 Fernando throughout September is predominantly from the south, with a peak proportion of 48% on September 1.

Wind Direction in September in San Fernando

Wind Direction in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%20%80%40%60%60%40%80%20%100%0%AugOctsoutheastnorth
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).

San Fernando 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 Fernando is essentially constant during September, remaining around 83°F throughout.

The highest average surface water temperature during September is 84°F on September 11.

Average Water Temperature in September in San Fernando

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

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).

The growing season in San Fernando typically lasts for 12 months (356 days), from around January 7 to around December 28, rarely starting after February 13, or ending before November 26.

The month of September in San Fernando is reliably fully within the growing season.

Time Spent in Various Temperature Bands and the Growing Season in September in San Fernando

Time Spent in Various Temperature Bands and the Growing Season in September in San Fernandogrowing seasongrowing seasonSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%AugOct100%Sep 16100%Sep 16coolcomfortablewarmhotswelteringcold
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 Fernando are rapidly increasing during September, increasing by 821°F, from 5,954°F to 6,775°F, over the course of the month.

Growing Degree Days in September in San Fernando

Growing Degree Days in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930305,800°F5,800°F6,000°F6,000°F6,200°F6,200°F6,400°F6,400°F6,600°F6,600°F6,800°F6,800°F7,000°F7,000°FAugOctSep 15,954°FSep 15,954°FSep 306,775°FSep 306,775°FSep 116,250°FSep 116,250°F
The average growing degree days accumulated over the course of September, with 25th to 75th and 10th to 90th percentile bands.

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 Fernando is essentially constant during September, remaining around 5.5 kWh throughout.

Average Daily Incident Shortwave Solar Energy in September in San Fernando

Average Daily Incident Shortwave Solar Energy in September in San FernandoSep1122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930300 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWhAugOctSep 15.5 kWhSep 15.5 kWhSep 305.5 kWhSep 305.5 kWhSep 115.5 kWhSep 115.5 kWh
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

For the purposes of this report, the geographical coordinates of San Fernando are 24.847 deg latitude, -98.148 deg longitude, and 144 ft elevation.

The topography within 2 miles of San Fernando contains only modest variations in elevation, with a maximum elevation change of 203 feet and an average elevation above sea level of 156 feet. Within 10 miles also contains only modest variations in elevation (443 feet). Within 50 miles contains only modest variations in elevation (3,550 feet).

The area within 2 miles of San Fernando is covered by cropland (89%) and artificial surfaces (11%), within 10 miles by cropland (89%) and shrubs (11%), and within 50 miles by cropland (60%) and water (18%).

This report illustrates the typical weather in San Fernando, 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, Brownsville-South Padre Island International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of San Fernando.

At a distance of 139 kilometers from San Fernando, 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 Fernando 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 © OpenStreetMap contributors.

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.

Please review our full terms contained on our Terms of Service page.