Weather in San Jose 🇨🇷
Monthly weather averages & travel planning
August
Avg Temp
24°C
Rain Days
28 days
Sun Hours
8 hrs
Humidity
82%
North America › 🇨🇷 Costa Rica › San Jose
Updated: March 2026
Is August a Good Time to Visit San Jose?
4/10
Fair
August is a fair time to visit San Jose (4/10). With 8 daily sunshine hours and only 28 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 9th sunniest of the year in San Jose. August suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 28 potential rain days. September offers a similar profile at lower hotel rates if dates are flexible. Watch out for prolonged rain stretches: with 28 wet days, a fully outdoor itinerary is risky. Build in museum days and covered market visits as contingency. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.
vs July:24°C avg high
Visiting San Jose in August means warm daytime temperatures peaking at 24°C. Factor in 28 potential rainy days and 82% average humidity when planning your daily activities.
24°C
75°F
Avg High
18°C
64°F
Avg Low
28 days
352 mm total
Rain Days
8h
per day avg
Sunshine
82%
Humid
Humidity
Temperature in San Jose in August
The 6°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. At 82% humidity, the 24°C daytime high feels 2-4°C warmer in practice: quick-dry fabrics and shade-seeking between noon and 3pm are the sensible response. UV index averages 8 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Winds are calm at an average 8 km/h, so wind-chill is not a factor in planning your clothing. In Fahrenheit: 75°F average high, 64°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Temperature Trends
High
Low
Rainfall (mm)
0-20 mm21-50 mm51-100 mm100+ mm
What to Wear in San Jose in August
Morning18°CBefore the day warms up
Afternoon24°CPeak daytime temperature
Evening21°CAfter sunset cools down
Packing for San Jose in August means dressing for 24°C days and 18°C evenings. A light cotton tee with a casual overshirt works well at 24°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 18°C, a modest 6°C drop that a light cardigan or denim jacket covers. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues. With 28 rain days expected, a compact travel umbrella is worth the bag space. A waterproof jacket is better than an umbrella if you plan full-day outdoor routes. At 82% average humidity, quick-dry synthetic or bamboo fabrics dry overnight and stay comfortable longer than cotton.
Local tip: San Jose sees heavy rain periods where a compact travel umbrella can feel inadequate. A packable waterproof jacket offers better coverage for prolonged downpours and leaves both hands free for maps and cameras.
Events in San Jose in August
August has no major festivals or public holidays in San Jose, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
What to Pack for San Jose in August
Based on 24°C average highs and 28 rainy days
- Light layers for morning and evening
- Breathable T-shirts and comfortable trousers
- UV-protective sunglasses
- Compact folding umbrella
- Waterproof outer layer or packable rain jacket
- Quick-dry clothing that recovers fast after a shower
- SPF 30+ sunscreen
- Comfortable walking shoes (a second pair lets the first air out overnight)
- Universal travel adapter
- Small day pack for city exploration
- Reusable water bottle
Best Activities in San Jose in August
- Explore outdoor markets and street food stallsMid-morning (10am-12pm)At 24°C, the temperature is ideal for extended walking without overheating
- Guided walking tour of the historic centreMorning or late afternoonComfortable temperatures allow several hours on foot without fatigue
- Visit rooftop viewpoints and observation decksGolden hour (1 hour before sunset)Warm clear evenings provide exceptional visibility for panoramic photography
- Day trip to the surrounding countryside or coastFull day (depart by 8am)August is reliably dry enough for rural day trips without weather risk
- Spend a morning in the national or city art museumOpens at 10am; arrive earlyWith 28 rain days expected, having a full-day indoor plan is practical insurance
- Cooking class focused on regional cuisineHalf-day sessions run 10am-1pm or 3-6pmIndoor activity that fills a rainy half-day with genuine cultural content
- Visit covered historical sites: cathedral, palace, or bazaarAny time; most crowded middayRoofed monuments and covered markets provide exploration without weather exposure
- Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningAugust brings distinct seasonal changes to public green spaces worth exploring
- Try the seasonal farmer's market for local produce and street foodSaturday morning markets typically 8am-1pmAugust seasonal produce is at peak availability, offering dishes not found at other times of year
Why is San Jose mild in August?
San Jose's August climate is governed by the Inter-Tropical Convergence Zone (ITCZ), which draws moisture-laden trade winds across the region, producing the characteristic wet season rainfall of warm tropical cities. Daytime heat peaks around 24°C, moderated slightly by afternoon convective showers. Overnight temperatures remain warm at 18°C because the humid air retains heat effectively. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Frequently Asked Questions
San Jose in August
In August, San Jose experiences average highs of 24°C (75°F) and lows of 18°C (64°F). Expect around 28 rainy days and 8 hours of sunshine per day, with humidity averaging 82%. The 6°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 8, so sun protection is advisable on clear days.
San Jose typically sees 28 rainy days in August, with total precipitation of around 352mm. This is a notably wet period. A waterproof jacket or compact umbrella is essential, and it is worth building indoor alternatives into your daily itinerary for the inevitable rainy stretches. For context, the driest month in San Jose typically sees 4-6 fewer rain days than August.
Pack light layers, a light jacket for evenings, comfortable walking shoes, and sunscreen for San Jose in August. Daytime temperatures of 24°C are pleasant, but the evening drop to 18°C means a jacket is essential if you plan to be out after dark. With 28 rainy days, bring a compact umbrella or waterproof jacket for unexpected showers. Comfortable walking shoes are a priority given the amount of ground most visitors cover.
August is a reasonable time to visit San Jose. Expect 28 rainy days, so pack a light rain layer for flexibility. Average temperatures of 24°C make outdoor exploration comfortable during the dry periods. With 8 daily sunshine hours, there are reliable windows of good weather to plan outdoor activities around, even if the month is not the driest on the calendar.
The average high temperature in San Jose in August is 24°C (75°F), and the average low is 18°C (64°F). The mean daily temperature is approximately 21°C (70°F). The day-to-night range of 6°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.
The best month to visit San Jose is generally February. February offers the most sunshine at 11 hours per day and only 11 rainy days. Average temperatures reach 25°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around February gives you the best chance of dry, bright weather.
August is shoulder or low season in San Jose, meaning fewer tourists and generally lower prices than peak months. With 8 sunshine hours and 28 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.
In August, San Jose suits a range of activities thanks to mild temperatures around 24°C. With frequent rain, indoor activities and covered attractions are a smart choice. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 8 hours of sunshine, parks and waterfront walks are particularly enjoyable.
August ranks 9th sunniest of the year in San Jose, with an average 8 daily sunshine hours. The driest months are February, January, and March. March is the hottest month (26°C avg high); November is the coolest (23°C). From here, temperatures fall 0°C into September. Compared to last month (July: 24°C high, 28 rain days), August is similarly warm and equally dry. August sits in the middle of the annual sunshine ranking for San Jose, offering a reasonable balance of good weather and manageable crowds.
Year-Round Climate
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 24°C | 17°C | 13 | 11h | View |
| February | 25°C | 17°C | 11 | 11h | View |
| March | 26°C | 17°C | 13 | 11h | View |
| April | 26°C | 18°C | 17 | 10h | View |
| May | 25°C | 18°C | 28 | 8h | View |
| June | 24°C | 18°C | 29 | 8h | View |
| July | 24°C | 18°C | 28 | 8h | View |
| August | 24°C | 18°C | 28 | 8h | View |
| September | 24°C | 18°C | 29 | 8h | View |
| October | 24°C | 18°C | 30 | 7h | View |
| November | 23°C | 18°C | 26 | 8h | View |
| December | 24°C | 17°C | 18 | 9h | View |
January
13 rain days, 11h sun
24°17°
February
11 rain days, 11h sun
25°17°
March
13 rain days, 11h sun
26°17°
April
17 rain days, 10h sun
26°18°
May
28 rain days, 8h sun
25°18°
June
29 rain days, 8h sun
24°18°
July
28 rain days, 8h sun
24°18°
August
28 rain days, 8h sun
24°18°
September
29 rain days, 8h sun
24°18°
October
30 rain days, 7h sun
24°18°
November
26 rain days, 8h sun
23°18°
December
18 rain days, 9h sun
24°17°
Other Months in San Jose
Plan Your Trip to San Jose
Data Sources for San Jose
Climate normals represent 30-year averages (1991-2020). Individual years may vary.