San Isidro in Spring
In spring (March, April and May), San Isidro sees average daytime highs around 25°C and overnight lows near 21°C, with 1198 mm of rain over about 85 wet days across the season. It is the warmest season of the year and the 3rd-wettest season.
Across spring, daytime highs hold fairly steady around 25°C. The sky is clear or mostly clear about 17% of the time across spring, and the air most often feels muggy.
Spring is San Isidro's 2nd-best season to visit on our travel score. San Isidro has little temperature swing across the year, so its calendar seasons blur — the season framing matters less here than for a place with four distinct seasons. For the whole year in context, see San Isidro's year-round climate.
- Avg daytime high
- 25°C
- warmest season of the year
- Avg overnight low
- 21°C
- Rainfall
- 1198 mm
- 85 wet days
- Avg wind
- 4 km/h
- Travel score
- 4.0
- 2nd-best season
- Months
- Mar · Apr · May
Temperature in San Isidro in Spring
Across spring, daytime highs hold fairly steady around 25°C.
A typical spring day in San Isidro reaches about 25°C and drops to 21°C overnight. The warmest of the three months is March, the coolest March.
San Isidro weather by month
How the three spring months (March, April and May) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 24° / 20° | 210 | 25.2 | 11.5 | 4.8 |
| Feb | 24° / 20° | 140 | 21.6 | 11.7 | 5.1 |
| Mar | 25° / 21° | 138 | 25.6 | 11.9 | 4.7 |
| Apr | 25° / 21° | 330 | 28.6 | 12.2 | 3.8 |
| May | 24° / 21° | 730 | 30.8 | 12.4 | 3.4 |
| Jun | 24° / 21° | 709 | 29.9 | 12.5 | 3.4 |
| Jul | 24° / 21° | 833 | 31 | 12.5 | 3.4 |
| Aug | 24° / 21° | 933 | 31 | 12.3 | 3.4 |
| Sep | 24° / 21° | 808 | 30 | 12.1 | 3.4 |
| Oct | 24° / 20° | 952 | 30.8 | 11.8 | 3.4 |
| Nov | 24° / 20° | 924 | 29.9 | 11.6 | 3.5 |
| Dec | 24° / 20° | 413 | 28.8 | 11.5 | 4.1 |
Cloud cover in Spring
The sky is clear or mostly clear about 17% of the time across spring.
Chance of precipitation in Spring
San Isidro gets around 1198 mm of rain over 85 wet days across spring. The line is the day-by-day chance of measurable precipitation.
Humidity in Spring
Most of spring feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Spring
Winds average 4 km/h across spring.
Sunrise & sunset in Spring
Daylight runs from about 11 h 48 min in early March to 12 h 30 min by late May. The lit band spans sunrise to sunset each day.
Solar energy in Spring
Average shortwave solar energy reaching the ground each day across spring, about 5.4 kWh/m².
Hazard calendar for San Isidro
In spring, San Isidro overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
San Isidro's rainy season runs May–November, when most of the year's rain falls.
Is spring a good time to visit San Isidro?
Our two travel scores rate spring for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
spring is a weaker month for outdoor sightseeing in San Isidro.
What to pack for San Isidro in Spring
From spring's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In spring, San Isidro sees daytime highs around 25°C and nights near 21°C. Pack rain gear and sun protection. Worth having: light clothes. About 85 days see rain.
Sea temperature near San Isidro in Spring
The nearest coast averages about 30°C across spring — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 28 km away) is warmest in March at about 30°C and coldest in November near 28°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 29 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 29 | 28 | 28 | 28 |
| Comfort | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Warm | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 29 | Tropical |
| Feb | 30 | Tropical |
| Mar | 30 | Tropical |
| Apr | 30 | Tropical |
| May | 29 | Tropical |
| Jun | 29 | Tropical |
| Jul | 29 | Tropical |
| Aug | 29 | Tropical |
| Sep | 29 | Tropical |
| Oct | 28 | Tropical |
| Nov | 28 | Warm |
| Dec | 28 | Tropical |
UV index in San Isidro in Spring
Clear-sky midday UV across spring averages around 14 (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 Isidro peaks around March 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 10 (extreme).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 12 | 14 | 15 | 14 | 13 | 13 | 12 | 13 | 13 | 12 | 12 | 10 |
| Level | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 12 | Extreme |
| Feb | 14 | Extreme |
| Mar | 15 | Extreme |
| Apr | 14 | Extreme |
| May | 13 | Extreme |
| Jun | 13 | Extreme |
| Jul | 12 | Extreme |
| Aug | 13 | Extreme |
| Sep | 13 | Extreme |
| Oct | 12 | Extreme |
| Nov | 12 | Extreme |
| Dec | 10 | Extreme |
Where is San Isidro?
San Isidro sits at 9.4°N, 83.7°W, 713 m above sea level, in Costa Rica. The nearest listed city is Manuel Antonio, 51 km away.
Topography around San Isidro
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Isidro.
Within 3 km, the terrain around San Isidro has only modest variations in elevation — a maximum elevation change of 211 m around an average of 723 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,363 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,764 m.
The land around San Isidro is covered by trees (40%), grassland (31%) and artificial surfaces (28%) within 3 km, trees (71%) and grassland (27%) within 16 km, and trees (67%) and water (22%) within 80 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
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 Isidro (9.3674°, -83.6971°, elevation 713 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.