Alajuela weather in August

In August, Alajuela sees average daytime highs of 25°C and overnight lows near 18°C, with 352 mm of rain across 26.4 wet days and about 12.3 hours of daylight. It is the 6th-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 0% of the time in August, and the air most often feels humid.

Daylight stretches from about 12 h 24 min at the start of August to 12 h 12 min by month's end. Set against the rest of the year, August is Alajuela's 9th-clearest and 8th-windiest month. For the whole year in context, see Alajuela's year-round climate.

Daytime high
25°
6th warmest
Overnight low
18°
9th coldest
Rainfall
352 mm
26.4 wet days
Daylight
12 h 18 min
5:31 AM – 5:51 PM
Cloud cover
91%
9th clearest
Wind
5 km/h
8th windiest
Solar energy
4.36 kWh/m²
Travel score
4.0
out of 10
Air quality
Good
PM10 18 µg/m³ · 2018

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 25°C through the month.

A typical August day in Alajuela reaches about 25°C in the afternoon and slips back to 18°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 26°C. Set against its neighbours, August runs on par with July and on par with September.

15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12518
22518
32518
42518
52518
62518
72518
82518
92518
102518
112518
122518
132518
142518
152518
162518
172518
182518
192517
202517
212517
222517
232517
242517
252517
262517
272517
282517
292517
302517
312517

Alajuela weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan25° / 16°295.811.57.8
Feb25° / 16°204.111.78.0
Mar26° / 17°205.211.97.5
Apr27° / 17°6211.212.26.2
May25° / 18°33324.712.54.2
Jun25° / 18°39027.312.63.8
Jul24° / 18°2672512.54.3
Aug25° / 18°35226.412.34.0
Sep24° / 17°42428.312.13.7
Oct24° / 17°44428.811.83.8
Nov24° / 17°22421.511.54.8
Dec24° / 17°7210.811.46.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 3% of August, with mostly cloudy or overcast conditions the remaining 96%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1496
2496
3496
4496
5496
6496
7595
8595
9595
10595
11595
12595
13595
14595
15595
16397
17397
18397
19397
20397
21397
22298
23298
24298
25298
26298
27298
28298
29298
30298
31298

Chance of precipitation in August

Any precipitation

Alajuela gets around 352 mm of rain over 26.4 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 85% 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 (%)
180
280
381
481
582
682
782
883
983
1083
1184
1284
1384
1485
1585
1685
1785
1886
1986
2086
2187
2287
2387
2488
2588
2689
2789
2889
2990
3090
3191

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid band about 64% of days. Sticky, muggy-or-worse air turns up on roughly 35% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)
106733
206634
306634
406634
506634
606634
706634
806634
906634
1006634
1106634
1206733
1306733
1406733
1506733
1606733
1706733
1806634
1906634
2006535
2106535
2216336
2316237
2416237
2516138
2606139
2706139
2806139
2906139
3006040
3106040

Wind in August

Winds average 5 km/h in August.

Across August, daily wind ranges from about 4 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 12 h 24 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 12 minutes over August. Sunrise moves from 5:30 AM to 5:31 AM, and sunset from 5:56 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:305:56
212.45:305:56
312.45:305:56
412.45:305:55
512.45:305:55
612.45:305:55
712.45:305:54
812.45:305:54
912.45:315:54
1012.45:315:53
1112.45:315:53
1212.45:315:53
1312.45:315:52
1412.35:315:52
1512.35:315:51
1612.35:315:51
1712.35:315:50
1812.35:315:50
1912.35:315:50
2012.35:315:49
2112.35:315:49
2212.35:315:48
2312.35:315:48
2412.35:315:47
2512.35:315:46
2612.25:315:46
2712.25:315:45
2812.25:315:45
2912.25:315:44
3012.25:315:44
3112.25:315:43

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.36 kWh/m².

For context, solar energy here swings from a low near 3.65 kWh/m² to a high of 5.95 kWh/m² in March across the year — August's 4.36 kWh/m² falls in the middle.

012345151015202531
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.3Bright
54.3Bright
64.3Bright
74.3Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.3Bright
154.3Bright
164.4Bright
174.4Bright
184.4Bright
194.4Bright
204.4Bright
214.4Bright
224.4Bright
234.4Bright
244.4Bright
254.4Bright
264.4Bright
274.4Bright
284.4Bright
294.4Bright
304.4Bright
314.4Bright
Planning a trip in August

Hazard calendar for Alajuela

In seasonPeak

In August, Alajuela sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Alajuela's rainy season runs May–November, when most of the year's rain falls.

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

Is August a good time to visit Alajuela?

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

4.0
Sightseeing
9th-best month of the year
3.6
Beach & pool
9th-best month of the year

August is a reasonable time to visit Alajuela for sightseeing.

What to pack for Alajuela in August

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

In August, Alajuela sees daytime highs around 25°C and nights near 18°C. Pack rain gear. Worth having: light clothes. About 26 days see rain.

rain gearlight clothes

Sea temperature near Alajuela 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 48 km away) is warmest in April at about 29°C and coldest in November near 28°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
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct28Tropical
Nov28Warm
Dec28Tropical

UV index in Alajuela 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 Alajuela peaks around February 22 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeFeb 22UV 14Dec 17UV 10
UV index (midday)Level
Jan11Extreme
Feb14Extreme
Mar14Extreme
Apr14Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec10Very high

Air quality in Alajuela 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 Alajuela is worst in May — around 19 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (January, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 1718 µg/m³Jan 149 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr17Moderate
May19Moderate
Jun17Moderate
Jul18Moderate
Aug17Moderate
Sep16Moderate
Oct14Moderate
Nov12Good
Dec10Good
Location & terrain

Where is Alajuela?

Alajuela sits at 10.0°N, 84.2°W, 955 m above sea level, in Costa Rica. The nearest listed city is Mercedes Norte, 9.0 km away.

Topography around Alajuela

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

Within 3 km, the terrain around Alajuela has only modest variations in elevation — a maximum elevation change of 200 m around an average of 945 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,297 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,470 m.

The land around Alajuela is covered by artificial surfaces (48%) and trees (32%) within 3 km, trees (56%), grassland (23%) and artificial surfaces (20%) within 16 km, and trees (68%) within 80 km.

3 km
200 m
16 km
2,297 m
80 km
3,470 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Mercedes Norte 9.0 km · San Francisco 10 km · Heredia 11 km · San Pablo 13 km · San Rafael 13 km · Colima 16 km · San Juan 16 km · San Jose 17 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 Alajuela (10.0172°, -84.2127°, elevation 955 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).