San Fernando weather in May

In May, San Fernando sees average daytime highs of 33°C and overnight lows near 23°C, with 49 mm of rain across 6.5 wet days and about 13.2 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs climb over the month, from about 32°C in the first days to 34°C by the end. The sky is clear or mostly clear about 40% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 54 min at the start of May to 13 h 24 min by month's end. Set against the rest of the year, May is San Fernando's 6th-clearest and 1st-windiest month. For the whole year in context, see San Fernando's year-round climate.

Daytime high
33°
4th warmest
Overnight low
23°
8th coldest
Rainfall
49 mm
6.5 wet days
Daylight
13 h 12 min
5:53 AM – 7:05 PM
Cloud cover
49%
6th clearest
Wind
16 km/h
1st windiest
Solar energy
6.36 kWh/m²
Travel score
3.8
out of 10

San Fernando is municipal seat of San Fernando, State of Tamaulipas, Mexico.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 32°C in the first days to 34°C by the end.

A typical May day in San Fernando reaches about 33°C in the afternoon and slips back to 23°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 37°C. Set against its neighbours, May runs about 2°C warmer than April and about 1°C cooler than June.

15°20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13222
23222
33222
43222
53322
63322
73322
83322
93323
103323
113323
123323
133323
143323
153323
163323
173323
183323
193323
203323
213323
223423
233424
243424
253424
263424
273424
283424
293424
303424
313424

How May really feels in San Fernando

Once humidity and wind are folded in, May averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
3 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Fernando weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan23° / 12°254.410.67.7
Feb25° / 14°203.911.17.8
Mar28° / 17°324.911.86.8
Apr31° / 20°455.212.65.1
May33° / 23°496.513.23.8
Jun35° / 25°639.913.52.8
Jul35° / 25°698.813.42.6
Aug35° / 25°579.512.92.4
Sep33° / 23°11914.512.23.3
Oct30° / 20°678.211.45.4
Nov26° / 16°355.310.87.5
Dec23° / 13°244.110.57.9

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 23% of May, with mostly cloudy or overcast conditions the remaining 37%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35743
45644
55743
65743
75743
85743
95842
105842
115941
125941
135941
146040
156040
166238
176238
186337
196337
206436
216535
226634
236733
246733
256931
267030
277030
287228
297327
307327
317426

Chance of precipitation in May

Any precipitation

San Fernando gets around 49 mm of rain over 6.5 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 21% and peaks near 26% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
115
215
315
415
516
616
717
818
919
1020
1120
1221
1322
1422
1522
1623
1723
1823
1923
2023
2123
2223
2323
2424
2524
2624
2724
2825
2925
3026
3126

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the oppressive band about 64% of days. Sticky, muggy-or-worse air turns up on roughly 91% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1561127493
2461126503
3451025533
4451024534
545923554
635823565
734822585
824722605
924722596
1024622606
1114622607
1213522627
1313522618
1413522618
1513522618
1602421649
1702421649
18024206410
19024206410
20024196510
21013186810
22013176811
23013166911
24013157011
25013137112
26012127312
27002117512
28002107513
2900197614
3000187615
3100187615

Wind in May

Winds average 16 km/h in May, the windiest month of the year.

Across May, daily wind ranges from about 15 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
717light breeze
817light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3115light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 54 min at the start of May to 13 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 30 minutes over May. Sunrise moves from 6:02 AM to 5:48 AM, and sunset from 6:57 PM to 7:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.96:026:57
212.96:026:58
313.06:016:58
413.06:006:59
513.05:596:59
613.05:597:00
713.05:587:00
813.15:577:01
913.15:577:01
1013.15:567:02
1113.15:557:02
1213.15:557:03
1313.25:547:03
1413.25:547:04
1513.25:537:04
1613.25:537:05
1713.25:527:05
1813.25:527:06
1913.35:517:07
2013.35:517:07
2113.35:507:08
2213.35:507:08
2313.35:507:09
2413.35:497:09
2513.35:497:10
2613.45:497:10
2713.45:487:11
2813.45:487:11
2913.45:487:12
3013.45:487:12
3113.45:487:12

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.36 kWh/m².

For context, solar energy here swings from a low near 3.35 kWh/m² to a high of 6.8 kWh/m² in July across the year — May's 6.36 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.2Intense
26.2Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.3Intense
86.3Intense
96.3Intense
106.3Intense
116.3Intense
126.3Intense
136.3Intense
146.3Intense
156.3Intense
166.3Intense
176.4Intense
186.4Intense
196.4Intense
206.4Intense
216.4Intense
226.5Intense
236.5Intense
246.5Intense
256.5Intense
266.5Intense
276.5Intense
286.6Intense
296.6Intense
306.6Intense
316.6Intense
Planning a trip in May

Hazard calendar for San Fernando

In seasonPeak

None of San Fernando's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

San Fernando sits in the Atlantic hurricane belt; the season peaks August–October.

San Fernando's rainy season runs June–October, when most of the year's rain falls.

Atlantic hurricane
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit San Fernando?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.8
Sightseeing
8th-best month of the year
6.8
Beach & pool
6th-best month of the year

May is a weaker month for outdoor sightseeing in San Fernando. The water and warmth also suit a beach or pool day.

What to pack for San Fernando in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, San Fernando sees daytime highs around 33°C and nights near 23°C. Pack light clothes and sun protection. About 7 days see rain.

light clothessun protection

Sea temperature near San Fernando in May

The nearest coast averages about 26°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 58 km away) is warmest in September at about 29°C and coldest in February near 20°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb20Refreshing
Mar21Refreshing
Apr23Refreshing
May26Warm
Jun28Warm
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct28Warm
Nov25Warm
Dec22Refreshing

UV index in San Fernando in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Fernando peaks around April 17 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 5 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highExtremeVery highHighApr 17UV 11Jan 10UV 5
UV index (midday)Level
Jan5High
Feb7High
Mar8Very high
Apr12Extreme
May9Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep9Very high
Oct9Very high
Nov6High
Dec5High

Air quality in San Fernando in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in San Fernando is worst in August — around 34 µg/m³ PM2.5 (moderate), about 5.6× the cleanest month (January, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 934 µg/m³Nov 186 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb8Good
Mar11Good
Apr14Moderate
May23Moderate
Jun28Moderate
Jul34Moderate
Aug34Moderate
Sep17Moderate
Oct7Good
Nov6Good
Dec6Good
Location & terrain

Where is San Fernando?

San Fernando sits at 24.8°N, 98.1°W, 44 m above sea level, in Mexico. The nearest listed city is Valle Hermoso, 98 km away.

Topography around San Fernando

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Fernando.

Within 3 km, the terrain around San Fernando has only modest variations in elevation — a maximum elevation change of 64 m around an average of 45 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 135 m; within 80 km, large variations in elevation — a maximum elevation change of 1,049 m.

The land around San Fernando is covered by trees (37%), artificial surfaces (29%) and shrubs (21%) within 3 km, cropland (35%), trees (30%) and shrubs (22%) within 16 km, and shrubs (30%) and cropland (21%) within 80 km.

3 km
64 m
16 km
135 m
80 km
1,049 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
May weather nearby: Valle Hermoso 98 km · Ciudad Río Bravo 127 km · Heroica Matamoros 132 km · Brownsville 134 km · Reynosa 138 km · Linares 143 km · Mercedes 147 km · Weslaco 147 km

Mexico travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 / 127 V · 60 Hz
Prices
≈ 54% of US
price level, 2025
GDP per capita
$13,889
2025
Happiness
7.0 / 10
World Happiness, 2025
Safe drinking water
43%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
12.8
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 440
Religion
Catholic 78%no religion 11%other Evangelical Churches 8%Jehovah Witness 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Fernando (24.8471°, -98.1488°, elevation 44 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).