Costa Rica San José Weather in May — Climate Guide
May in San José is high
San José Weather in May — Quick Answer
As of 2026- Avg temp
- 26° / 17°
- Rainfall
- 230mm · 17 days
- Crowds
- Moderate
As of 2026, San José in May averages a high of 26°C and low of 17°C with 230mm of rain over about 17 days. Green (wet) season begins — around 26°C/17°C with clear mornings and afternoon rain. Light clothing plus a reliable rain jacket and quick-dry layers. UV still high. Warm layer for the highlands.
May is high for San José.
May marks the start of the green (wet) season in San José — the landscapes turn vivid green and the crowds thin out. Temperatures barely change (around 26°C/17°C), but rainfall jumps sharply (about 230mm), arriving as predictable afternoon and evening showers after clearer mornings.
This is the value sweet spot: prices drop 30-40% from the dry-season peak, tour availability opens up, and the country looks its lushest. The key is timing your day — do the volcanoes, beaches, and hikes in the morning while it's bright, and keep afternoons flexible for the rain.
Travel score
San José May Weather Stats
Avg High
26°C
Avg Low
17°C
Rainy Days
17
230mm total
Sunshine
6h
Daily avg
Humidity
78%
muggy
UV Index
11
Extreme
Wind
9 km/h
Gusts 18
Crowds
Moderate
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
15 μg/m³
PM10
28 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
28°C
Nighttime
18°C
Humidity and wind affect how the actual temperature feels.
Wind
9 km/h
Max gust 18 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Lush green-season landscapes
- 30-40% lower prices, fewer crowds
- Clear mornings for activities
- Good value on tours and lodging
Cons
- Frequent afternoon/evening rain
- Higher humidity
- Some roads muddier in rural areas
- Plans need morning flexibility
May Events & Festivals
- Green season begins — lower prices, lush landscapes
- Labor Day (May 1) — public holiday
- Afternoon-shower pattern sets in
San José in May — Full Picture
May marks the start of the green (wet) season in San José — the landscapes turn vivid green and the crowds thin out. Temperatures barely change (around 26°C/17°C), but rainfall jumps sharply (about 230mm), arriving as predictable afternoon and evening showers after clearer mornings.
This is the value sweet spot: prices drop 30-40% from the dry-season peak, tour availability opens up, and the country looks its lushest. The key is timing your day — do the volcanoes, beaches, and hikes in the morning while it's bright, and keep afternoons flexible for the rain.
Mornings often offer good volcano-view odds before the clouds build, so an early Poás trip can still pay off. The Caribbean side (Tortuguero) follows a different pattern and can be drier now.
Bring a proper rain jacket, quick-dry clothes, and waterproof footwear, plus a warm layer for the cool, misty cloud forest, which lives up to its name year-round.
What to Wear & What to Pack
Green (wet) season begins — around 26°C/17°C with clear mornings and afternoon rain. Light clothing plus a reliable rain jacket and quick-dry layers. UV still high. Warm layer for the highlands.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current26°C
16.7°C
8/mo
Summer (Jun·Jul·Aug)
26°C
17°C
17.7/mo
Autumn (Sep·Oct·Nov)
25.3°C
16°C
18/mo
Winter (Dec·Jan·Feb)
24.3°C
15°C
2.3/mo
San José Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| January (Best) | 24° | 15° | 2d·15mm | 8h | 70% | 11 | Very busy | Peak |
| February (Best) | 25° | 15° | 1d·10mm | 8.5h | 68% | 11 | Busy | Peak |
| March (Best) | 26° | 16° | 2d·20mm | 8.5h | 65% | 12 | Busy | Peak |
| April (Best) | 26° | 17° | 5d·50mm | 7.5h | 68% | 12 | Busy | Peak |
| 26° | 17° | 17d·230mm | 6h | 78% | 11 | Moderate | Shoulder | |
| 26° | 17° | 19d·245mm | 5.5h | 80% | 11 | Moderate | Shoulder | |
| 26° | 17° | 16d·180mm | 6h | 78% | 11 | Busy | Shoulder | |
| 26° | 17° | 18d·210mm | 5.5h | 80% | 11 | Moderate | Shoulder | |
| 26° | 16° | 20d·280mm | 5h | 82% | 10 | Quiet | Low season | |
| 25° | 16° | 21d·295mm | 5h | 82% | 10 | Quiet | Low season | |
| 25° | 16° | 13d·130mm | 6h | 78% | 10 | Moderate | Shoulder | |
| December (Best) | 24° | 15° | 4d·40mm | 7.5h | 72% | 11 | Very busy | Peak |
View Other Months
San José May Hotel Picks
Frequently Asked Questions
Is May a good time to visit San José?
San José in May is high. Tourist crowds are moderate and flight/hotel prices are shoulder.
What's the average temperature in San José in May?
San José May averages a high of 26°C and a low of 17°C.
Does it rain much in San José in May?
San José May averages 230mm of rainfall over about 17 rainy days.
What should I wear in San José in May?
Green (wet) season begins — around 26°C/17°C with clear mornings and afternoon rain. Light clothing plus a reliable rain jacket and quick-dry layers. UV still high. Warm layer for the highlands.
What time are sunrise and sunset in San José in May?
San José May sunrise is 05:20 and sunset is 17:50, with 12h 30min of daylight.
What's the air quality like in San José in May?
San José May air quality (AQI) averages 40, rated Good. PM2.5 averages 15μg/m³.
What activities are recommended in San José in May?
In May, San José is great for Morning volcano trips, Green-season value tours, Arenal hot springs (rain-friendly).
Is May peak season in San José?
San José May crowds are moderate and prices are shoulder. You can travel relatively comfortably without long queues.
Best Months to Visit San José
View Other Months
Planning a May trip to San José?
You've checked the weather — next come the budget and the route.
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.