San José weather in August
August in San José: hot, soaked, with clean air — a gamble, with 27 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#7 of 12 months in San José · #1071 of 1413 destinations to visit in August · comfort 61/100 (tier C)
- Days
- 28°C
- Nights
- 18°C
- Wet days
- 27
- Sun
- 8.1 h
- Humidity
- 91%
- Daylight
- 12 h

Traveller notes on San José in August
Forum posters generally rate August as a good month to visit Costa Rica overall, describing a typical lowland or coastal day as sunny and hot in the morning with rain, sometimes heavy, moving in during the afternoon or evening - a pattern posters say leaves the landscape noticeably greener. San Jose itself, at over 1,100m elevation, runs noticeably milder than those hotter coastal descriptions, with comfortable daytime highs rather than genuine heat. Posters are direct that late August specifically can turn genuinely rainy, and while Pacific-slope rain is usually confined to afternoon and evening, posters emphasize there's no guarantee during rainy season. One visitor's second-half-of-August trip found mostly good weather, though posters are consistent that predicting exact conditions for specific dates isn't really possible. Posters generally rate August as workable and even good for a San José-area visit, rain gear recommended regardless.
Other months in San José
February is deep in Costa Rica's dry season, and San José sits at altitude, so it runs cooler than the coasts — near 26°C by day, dropping to 17 at night. "Dry season" is the forum's own phrase and their own caveat: it does not mean it cannot rain, and eight wet days is the record's answer. Regulars pack an umbrella regardless. Two regional notes matter more than the capital's own weather: the Caribbean side is reliably rainier and cloudier than the Pacific in February, and Guanacaste gets serious wind this month while La Fortuna, Monteverde and Manuel Antonio generally do not.
Add your own note from San José's card on the map.
San José climate normals — August
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in San José in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyRomeria to Cartago, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for San José's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherSan José's weather peaks January–March, best around February.
Best weatherFair weatherToughest weather
What's on in San José in August
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Green season
1 May – 30 Nov · usuallyOff-season shutdownCosta Rica's low season: mornings are usually clear and the rain comes in afternoon bursts. Hotel rates drop, the central valley turns green, and day trips to volcanoes are best started early. Source ↗
- Festival
Romeria to Cartago
25 Jul – 2 AugPilgrimage seasonCrowdedClosuresHundreds of thousands walk from San Jose to the basilica of La Negrita in Cartago, most overnight on 1 August. Traffic on the Cartago road is restricted, and 2 August is a national holiday. Source ↗
- Season
Wet season
MonsoonRisk27 rainy days and about 310 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of San José — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is San José?
San José in August — FAQ
- Is August a good time to visit San José?
- August in San José: hot, soaked, with clean air — a gamble, with 27 rainy days. It ranks #7 of 12 months for San José on SeasonMap's comfort score (61/100).
- What is the weather like in San José in August?
- In August, San José averages a daily high of 27.9°C and a low of 18.3°C, with about 309.9 mm of rain over roughly 26.6 rainy days.
- What is the air quality in San José in August?
- San José has a mean US Air Quality Index of about 33 in August.
Within 300 km: Jacó's Humpback whales around 15 Jul – 15 Nov, and Tortuguero's Green turtle nesting on 1 Jul – 31 Oct.