San José weather in August

In August, San José sees average daytime highs of 27°C and overnight lows near 23°C, with 259 mm of rain across 30.5 wet days and about 12.4 hours of daylight. It is the 6th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 4% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 12 h 30 min at the start of August to 12 h 12 min by month's end. Set against the rest of the year, August is San José's 10th-clearest and 8th-windiest month. For the whole year in context, see San José's year-round climate.

Daytime high
27°
6th warmest
Overnight low
23°
10th coldest
Rainfall
259 mm
30.5 wet days
Daylight
12 h 24 min
5:34 AM – 5:56 PM
Cloud cover
83%
10th clearest
Wind
13 km/h
8th windiest
Solar energy
4.65 kWh/m²
Travel score
3.4
out of 10

San José is populated place in Upala district of Costa Rico.

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical August day in San José reaches about 27°C in the afternoon and slips back to 23°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 28°C. Set against its neighbours, August runs on par with July and on par with September.

20°23°25°28°30°151015202531
Avg high (°C)Avg low (°C)
12723
22723
32723
42723
52723
62723
72723
82723
92723
102723
112723
122723
132723
142723
152723
162723
172723
182723
192723
202723
212723
222723
232723
242723
252723
262723
272723
282723
292723
302723
312723

San José weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 22°17126.811.44.5
Feb27° / 22°11322.111.64.8
Mar28° / 23°8019.811.95.3
Apr28° / 23°6318.112.24.8
May28° / 24°22326.712.53.7
Jun27° / 24°28129.412.63.3
Jul27° / 23°30830.612.63.4
Aug27° / 23°25930.512.43.4
Sep27° / 23°26029.312.13.4
Oct27° / 23°29929.311.83.5
Nov26° / 23°26226.211.54.0
Dec26° / 22°21427.311.44.2

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 4% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 10% of August, with mostly cloudy or overcast conditions the remaining 86%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11486
21486
31486
41387
51486
61486
71486
81486
91486
101486
111486
121387
131387
141387
151387
161486
171486
181486
191486
201486
211486
221486
231486
241486
251585
261585
271585
281585
291585
301585
311585

Chance of precipitation in August

Any precipitation

San José gets around 259 mm of rain over 30.5 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 98% and peaks near 99% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
198
298
398
498
598
698
798
898
998
1098
1199
1299
1399
1499
1599
1699
1799
1899
1999
2099
2199
2299
2398
2498
2598
2698
2798
2898
2997
3097
3197

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the oppressive band about 100% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in August

Winds average 13 km/h in August.

Across August, daily wind ranges from about 11 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2112light breeze
2212light breeze
2312light breeze
2412calm
2512calm
2612calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 12 h 30 min at the start of August to 12 h 12 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 5:32 AM to 5:34 AM, and sunset from 6:01 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.55:326:01
212.55:326:01
312.55:326:01
412.55:326:00
512.55:336:00
612.45:336:00
712.45:335:59
812.45:335:59
912.45:335:59
1012.45:335:58
1112.45:335:58
1212.45:335:57
1312.45:335:57
1412.45:345:57
1512.45:345:56
1612.45:345:56
1712.45:345:55
1812.35:345:55
1912.35:345:54
2012.35:345:54
2112.35:345:53
2212.35:345:53
2312.35:345:52
2412.35:345:51
2512.35:345:51
2612.35:345:50
2712.35:345:50
2812.35:345:49
2912.25:345:48
3012.25:345:48
3112.25:345:47

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.65 kWh/m².

For context, solar energy here swings from a low near 3.98 kWh/m² to a high of 6.04 kWh/m² in April across the year — August's 4.65 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.6Bright
104.6Bright
114.6Bright
124.6Bright
134.6Bright
144.6Bright
154.6Bright
164.6Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
314.8Bright
Planning a trip in August

Is August a good time to visit San José?

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

3.4
Sightseeing
9th-best month of the year
3.4
Beach & pool
11th-best month of the year

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

What to pack for San José in August

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

In August, San José sees daytime highs around 27°C and nights near 23°C. Pack rain gear. Worth having: light clothes and sun protection. About 31 days see rain.

rain gearlight clothessun protection

Sea temperature near San José in August

The nearest coast averages about 29°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 65 km away) is warmest in May at about 29°C and coldest in February near 27°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr29Tropical
May29Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov28Warm
Dec27Warm

UV index in San José in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 13 (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 José peaks around March 18 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 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 18UV 14Dec 16UV 9
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar14Extreme
Apr14Extreme
May13Extreme
Jun13Extreme
Jul12Extreme
Aug13Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec9Very high

Air quality in San José 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 José is worst in July — around 23 µg/m³ PM2.5 (moderate), about 3.8× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1622 µg/m³Dec 166 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar9Good
Apr19Moderate
May21Moderate
Jun19Moderate
Jul23Moderate
Aug18Moderate
Sep13Moderate
Oct9Good
Nov6Good
Dec6Good
Location & terrain

Where is San José?

San José sits at 11.0°N, 85.1°W, 50 m above sea level, in Costa Rica. The nearest listed city is San Carlos, 44 km away.

San CarlosLiberiaCañasLa FortunaMonteverdeEl CastilloSan Juan del Sur

Topography around San José

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

Within 3 km, the terrain around San José has only modest variations in elevation — a maximum elevation change of 55 m around an average of 51 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 659 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,977 m.

The land around San José is covered by grassland (51%) and trees (48%) within 3 km, trees (59%) and grassland (36%) within 16 km, and trees (45%), water (27%) and grassland (24%) within 80 km.

3 km
55 m
16 km
659 m
80 km
1,977 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: San Carlos 44 km · Liberia 48 km · Cañas 58 km · La Fortuna 76 km · Monteverde 80 km · El Castillo 81 km · San Juan del Sur 87 km · Rivas 93 km

Costa Rica travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 59% of US
price level, 2025
GDP per capita
$19,970
2025
Happiness
7.4 / 10
World Happiness, 2025
Safe drinking water
81%
of population, 2024
Homicide rate
17.7
per 100k, 2023
Road deaths
14.8
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 516
Religion
Roman Catholic 48%none 27%Evangelical and Pentecostal 20%other 3%

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 José (10.9519°, -85.1357°, elevation 50 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. 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).