San Marcos weather in August

In August, San Marcos sees average daytime highs of 31°C and overnight lows near 22°C, with 230 mm of rain across 26 wet days and about 12.5 hours of daylight. It is the 8th-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 10% of the time in August, and the air most often feels muggy.

Daylight stretches from about 12 h 36 min at the start of August to 12 h 18 min by month's end. Set against the rest of the year, August is San Marcos's 10th-clearest and 9th-windiest month. For the whole year in context, see San Marcos's year-round climate.

Daytime high
31°
8th warmest
Overnight low
22°
10th coldest
Rainfall
230 mm
26 wet days
Daylight
12 h 30 min
5:47 AM – 6:15 PM
Cloud cover
75%
10th clearest
Wind
4 km/h
9th windiest
Solar energy
5.64 kWh/m²
Travel score
2.9
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical August day in San Marcos reaches about 31°C in the afternoon and slips back to 22°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 33°C. Set against its neighbours, August runs on par with July and about 1°C warmer than September.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13122
23122
33122
43122
53122
63122
73122
83122
93122
103122
113122
123122
133122
143122
153122
163122
173122
183122
193122
203122
213122
223122
233122
243122
253022
263022
273022
283022
293022
303022
313022

How August really feels in San Marcos

Once humidity and wind are folded in, August 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
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

San Marcos weather by month

How August compares with the rest of the year at a glance. August is the 8th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 20°20.611.35.5
Feb33° / 20°20.511.54.9
Mar33° / 21°102.911.94.3
Apr33° / 22°5011.312.33.7
May31° / 22°22224.912.62.9
Jun30° / 22°24826.312.82.9
Jul31° / 22°18622.312.73.1
Aug31° / 22°2302612.52.9
Sep30° / 22°30328.412.12.8
Oct29° / 21°23223.311.73.6
Nov31° / 20°457.611.45.1
Dec31° / 20°71.411.25.6

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 16% of August, with mostly cloudy or overcast conditions the remaining 75%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13070
23070
32971
42872
52872
62971
72872
82872
92773
102773
112773
122773
132773
142674
152674
162872
172773
182773
192773
202674
212575
222575
232377
242377
252377
262179
272179
282179
291981
301981
311882

Chance of precipitation in August

Any precipitation

San Marcos gets around 230 mm of rain over 26 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 84% and peaks near 91% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
176
277
378
478
579
680
780
881
981
1082
1182
1282
1383
1483
1583
1683
1783
1884
1984
2084
2185
2285
2386
2487
2587
2688
2789
2889
2990
3091
3191

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the muggy band about 59% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)
117128
217029
317029
416930
516930
616831
716831
816732
916732
1016633
1116633
1216534
1316435
1416336
1516237
1616138
1716039
1815940
1915742
2015643
2105545
2205446
2305248
2405149
2504951
2604852
2704753
2804654
2904555
3004555
3104456

Wind in August

Winds average 4 km/h in August.

Across August, daily wind ranges from about 4 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 12 h 36 min at the start of August to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over August. Sunrise moves from 5:44 AM to 5:48 AM, and sunset from 6:21 PM to 6:05 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.65:446:21
212.65:456:21
312.65:456:20
412.65:456:20
512.65:456:20
612.65:456:19
712.65:466:19
812.55:466:18
912.55:466:18
1012.55:466:18
1112.55:466:17
1212.55:476:17
1312.55:476:16
1412.55:476:16
1512.55:476:15
1612.55:476:15
1712.45:476:14
1812.45:476:13
1912.45:476:13
2012.45:486:12
2112.45:486:12
2212.45:486:11
2312.45:486:10
2412.45:486:10
2512.45:486:09
2612.35:486:09
2712.35:486:08
2812.35:486:07
2912.35:486:07
3012.35:486:06
3112.35:486:05

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.64 kWh/m².

For context, solar energy here swings from a low near 4.73 kWh/m² to a high of 6.23 kWh/m² in March across the year — August's 5.64 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.9Bright
45.9Bright
55.9Bright
65.8Bright
75.8Bright
85.8Bright
95.8Bright
105.8Bright
115.8Bright
125.7Bright
135.7Bright
145.7Bright
155.7Bright
165.6Bright
175.6Bright
185.6Bright
195.6Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.3Bright
305.3Bright
315.3Bright
Planning a trip in August

Hazard calendar for San Marcos

In seasonPeak

In August, San Marcos sits inside its atlantic hurricane and monsoon season. The full year is below, with each hazard's peak months called out.

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

San Marcos's monsoon runs May–October, when most of the year's rain falls.

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

Is August a good time to visit San Marcos?

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

2.9
Sightseeing
9th-best month of the year
4.2
Beach & pool
10th-best month of the year

August is a weaker month for outdoor sightseeing in San Marcos.

What to pack for San Marcos in August

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

In August, San Marcos sees daytime highs around 31°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.

light clothesrain gearsun protection

Sea temperature near San Marcos in August

The nearest coast averages about 30°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 32 km away) is warmest in August at about 30°C and coldest in January near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr29Tropical
May30Tropical
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in San Marcos in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 12 (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 Marcos peaks around March 21 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highMar 21UV 13Dec 12UV 9
UV index (midday)Level
Jan9Very high
Feb13Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug12Extreme
Sep11Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Air quality in San Marcos in August

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in San Marcos is worst in April — around 43 µg/m³ PM2.5 (poor), about 1.6× the cleanest month (September, 26 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModeratePoorApr 1942 µg/m³Sep 1026 µg/m³
PM2.5 (µg/m³)Level
Jan34Moderate
Feb35Moderate
Mar35Poor
Apr43Poor
May40Poor
Jun27Moderate
Jul30Moderate
Aug27Moderate
Sep26Moderate
Oct29Moderate
Nov35Moderate
Dec36Poor
Location & terrain

Where is San Marcos?

San Marcos sits at 13.7°N, 89.2°W, 733 m above sea level, in El Salvador. The nearest listed city is San Salvador, 3.0 km away.

Topography around San Marcos

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

Within 3 km, the terrain around San Marcos has significant variations in elevation — a maximum elevation change of 567 m around an average of 854 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,865 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,703 m.

The land around San Marcos is covered by trees (69%) and artificial surfaces (27%) within 3 km, trees (72%) within 16 km, and trees (46%), water (25%) and grassland (21%) within 80 km.

3 km
567 m
16 km
1,865 m
80 km
2,703 m
treesshrubsgrasslandcroplandartificial surfaceswatermangroves
August weather nearby: San Salvador 3.0 km · Delgado 7.0 km · Mejicanos 7.0 km · Soyapango 7.0 km · Cuscatancingo 7.0 km · Antiguo Cuscatlán 8.0 km · Ayutuxtepeque 9.0 km · Ilopango 9.0 km

El Salvador travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
115 V · 60 Hz
Prices
≈ 41% of US
price level, 2025
GDP per capita
$5,767
2025
Happiness
6.6 / 10
World Happiness, 2025
Homicide rate
7.9
per 100k, 2022
Road deaths
20.9
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 523
Religion
Roman Catholic 44%Protestant 40%none 16%

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 Marcos (13.6611°, -89.1825°, elevation 733 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).