San Juan weather in August

In August, San Juan sees average daytime highs of 30°C and overnight lows near 22°C, with 154 mm of rain across 21.8 wet days and about 11.9 hours of daylight. It is the 4th-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 13% of the time in August, and the air most often feels oppressive.

Daylight stretches from about 11 h 48 min at the start of August to 11 h 54 min by month's end. Set against the rest of the year, August is San Juan's 1st-clearest and 9th-windiest month. For the whole year in context, see San Juan's year-round climate.

Daytime high
30°
4th warmest
Overnight low
22°
2nd coldest
Rainfall
154 mm
21.8 wet days
Daylight
11 h 54 min
6:01 AM – 5:53 PM
Cloud cover
66%
1st clearest
Wind
4 km/h
9th windiest
Solar energy
4.77 kWh/m²
Travel score
3.6
out of 10

San Juan is human settlement.

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 30°C through the month.

A typical August day in San Juan reaches about 30°C in the afternoon and slips back to 22°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 32°C. Set against its neighbours, August runs about 1°C warmer than July and on par with September.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13022
23022
33022
43022
53022
63022
73022
83022
93022
103022
113022
123022
133022
143022
153022
163022
173022
183023
193023
203023
213023
223023
233023
243023
253023
263023
273023
283023
293023
303023
313023

How August really feels in San Juan

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 Juan weather by month

How August compares with the rest of the year at a glance. August is the 4th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 24°25225.912.23.0
Feb30° / 24°23324.512.12.9
Mar30° / 24°30428.4122.8
Apr30° / 23°29427.311.92.9
May29° / 23°27126.711.83.2
Jun29° / 23°2192511.83.4
Jul29° / 22°16623.311.83.8
Aug30° / 22°15421.811.93.6
Sep31° / 23°17923.5123.2
Oct31° / 23°20125.912.12.9
Nov30° / 24°23525.812.22.9
Dec30° / 24°26327.212.22.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 23% of August, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24159
34060
44159
54159
64060
74060
83961
93862
103862
113763
123664
133664
143664
153664
163565
173466
183466
193466
203466
213367
223367
233367
243268
253367
263367
273268
283268
293268
303169
313169

Chance of precipitation in August

Any precipitation

San Juan gets around 154 mm of rain over 21.8 wet days in August, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 71% and peaks near 76% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
170
270
369
469
568
668
768
868
968
1068
1168
1268
1368
1469
1569
1669
1769
1870
1970
2071
2171
2272
2373
2473
2574
2674
2775
2875
2975
3076
3176

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 72% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1147718
2147619
3147619
4147520
5147520
6147421
7147421
8147322
9147322
10147322
11147322
12147223
13147223
14147223
15147223
16147223
17147223
18147124
19137224
20137125
21137026
22137026
23136927
24136927
25036928
26036928
27036829
28036730
29036730
30026731
31026632

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 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
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 11 h 48 min at the start of August to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over August. Sunrise moves from 6:04 AM to 5:55 AM, and sunset from 5:54 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:045:54
211.86:045:54
311.86:045:54
411.86:045:54
511.86:045:54
611.86:035:54
711.86:035:54
811.96:035:54
911.96:035:54
1011.96:035:54
1111.96:025:54
1211.96:025:54
1311.96:025:54
1411.96:025:54
1511.96:015:54
1611.96:015:53
1711.96:015:53
1811.96:005:53
1911.96:005:53
2011.96:005:53
2111.95:595:53
2211.95:595:53
2311.95:595:52
2411.95:585:52
2511.95:585:52
2611.95:575:52
2711.95:575:52
2811.95:575:52
2911.95:565:51
3011.95:565:51
3111.95:555:51

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.77 kWh/m².

For context, solar energy here swings from a low near 3.76 kWh/m² to a high of 5.14 kWh/m² in September across the year — August's 4.77 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.6Bright
74.6Bright
84.6Bright
94.6Bright
104.6Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.8Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in August

Is August a good time to visit San Juan?

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

3.6
Sightseeing
2nd-best month of the year
4.9
Beach & pool
1st-best month of the year

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

What to pack for San Juan in August

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

In August, San Juan sees daytime highs around 30°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 22 days see rain.

light clothesrain gearsun protection

UV index in San Juan in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 Juan peaks around February 13 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near August 14 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 highExtremeFeb 13UV 16Aug 14UV 9
UV index (midday)Level
Jan15Extreme
Feb16Extreme
Mar15Extreme
Apr12Extreme
May13Extreme
Jun11Extreme
Jul10Extreme
Aug9Very high
Sep12Extreme
Oct12Extreme
Nov12Extreme
Dec12Extreme

Air quality in San Juan 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 Juan is worst in March — around 15 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (June, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodMar 915 µg/m³Jun 169 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb15Moderate
Mar15Moderate
Apr12Moderate
May10Good
Jun9Good
Jul10Good
Aug13Moderate
Sep15Moderate
Oct10Good
Nov11Good
Dec12Moderate
Location & terrain

Where is San Juan?

San Juan sits at 3.8°S, 73.3°W, 99 m above sea level, in Peru. The nearest listed city is Belen, 4.0 km away.

RequenaAtalaia do NorteBenjamin ConstantLeticiaTabatingaYurimaguas

Topography around San Juan

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

Within 3 km, the terrain around San Juan has only modest variations in elevation — a maximum elevation change of 37 m around an average of 94 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 78 m; within 80 km, only modest variations in elevation — a maximum elevation change of 116 m.

The land around San Juan is covered by trees (53%) and artificial surfaces (30%) within 3 km, trees (79%) within 16 km, and trees (96%) within 80 km.

3 km
37 m
16 km
78 m
80 km
116 m
treesgrasslandartificial surfaceswater
August weather nearby: Belen 4.0 km · Iquitos 4.0 km · Requena 156 km · Atalaia do Norte 349 km · Benjamin Constant 367 km · Leticia 374 km · Tabatinga 374 km · Yurimaguas 394 km

Peru travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B / C
220 V · 60 Hz
Prices
≈ 51% of US
price level, 2025
GDP per capita
$9,684
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
49%
of population, 2024
Homicide rate
8.6
per 100k, 2021
Road deaths
13.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 519
Religion
Catholic 76%Evangelical Christian 16%no religion 5%other religions 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 Juan (-3.7761°, -73.2814°, elevation 99 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. 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).