Climate and average weather in Costa Rica
In Costa Rica, the summers are oppressive, sweltering, showery, and partly cloudy and the winters are warm and mostly clear.
Over the course of the year, the temperature in Costa Rica typically varies from 14°C to 34°C, and is rarely below 11°C or above 36°C. July is the hottest month of the year, while January is the coldest.
Based on the travel score, the best time of year to visit Costa Rica for warm-weather activities is from late November to mid April.
- Hottest
- Jul
- 34°
- Coldest
- Jan
- 14°
- Wettest
- Sep
- 175 mm
- Driest
- May
- 1 mm
- Rain / yr
- 590 mm
- 66 wet days
- Daylight
- 10.5–13.5 h
- shortest–longest
- Elevation
- 30 m
- 24.6°N
- Clearest
- May
- 22% cloud
Costa Rica is town in Culiacán Municipality, State of Sinaloa, Mexico.
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Costa Rica weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late November to mid April.
Temperature through the year
Daily average highs and lows in Costa Rica, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 5.5 months, from May 15 to October 29, with daily high temperatures above 31°C. The hottest month of the year in Costa Rica is July, with an average high of 34°C and low of 26°C.
The cool season lasts 3.1 months, from December 7 to March 10, with daily high temperatures below 27°C. The coldest month of the year in Costa Rica is January, with an average low of 14°C and high of 26°C.
Days typically run about 10°C warmer than nights, with the widest day–night swing (around 12°C) in April.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 26 | 26 | 27 | 29 | 31 | 33 | 34 | 33 | 33 | 32 | 30 | 26 |
| Avg low (°C) | 14 | 15 | 16 | 18 | 21 | 25 | 26 | 26 | 26 | 24 | 19 | 15 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 26 | 14 |
| Feb | 26 | 15 |
| Mar | 27 | 16 |
| Apr | 29 | 18 |
| May | 31 | 21 |
| Jun | 33 | 25 |
| Jul | 34 | 26 |
| Aug | 33 | 26 |
| Sep | 33 | 26 |
| Oct | 32 | 24 |
| Nov | 30 | 19 |
| Dec | 26 | 15 |
How hot and cold Costa Rica really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the hottest afternoons, once humidity is folded in, Costa Rica feels like about 43°C (around July 31). About 188 days a year carry some heat stress, and 116 of them tip into dangerous heat (feels-like above 39°C), peaking in July.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 25 | 26 | 28 | 30 | 33 | 38 | 42 | 42 | 42 | 38 | 31 | 26 |
| Air high (°C) | 26 | 26 | 27 | 29 | 31 | 33 | 34 | 33 | 33 | 32 | 30 | 26 |
| Feels-like low (°C) | 14 | 15 | 16 | 18 | 21 | 25 | 26 | 26 | 26 | 24 | 19 | 15 |
| Air low (°C) | 14 | 15 | 16 | 18 | 21 | 25 | 26 | 26 | 26 | 24 | 19 | 15 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 25 | 26 | 14 | 14 |
| Feb | 26 | 26 | 15 | 15 |
| Mar | 28 | 27 | 16 | 16 |
| Apr | 30 | 29 | 18 | 18 |
| May | 33 | 31 | 21 | 21 |
| Jun | 38 | 33 | 25 | 25 |
| Jul | 42 | 34 | 26 | 26 |
| Aug | 42 | 33 | 26 | 26 |
| Sep | 42 | 33 | 26 | 26 |
| Oct | 38 | 32 | 24 | 24 |
| Nov | 31 | 30 | 19 | 19 |
| Dec | 26 | 26 | 15 | 15 |
Average hourly temperature in Costa Rica
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 34°C, and coldest before dawn in January, near 14°C.
Costa Rica weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 26° / 14° | 13 | 1.7 | 10.6 | 8.4 |
| Feb | 26° / 15° | 14 | 1.6 | 11.1 | 8.3 |
| Mar | 27° / 16° | 3 | 0.5 | 11.8 | 8.2 |
| Apr | 29° / 18° | 1 | 0.2 | 12.6 | 6.9 |
| May | 31° / 21° | 1 | 0.2 | 13.2 | 5.7 |
| Jun | 33° / 25° | 14 | 2 | 13.5 | 4.5 |
| Jul | 34° / 26° | 108 | 13.7 | 13.4 | 2.9 |
| Aug | 33° / 26° | 168 | 19.1 | 12.9 | 2.6 |
| Sep | 33° / 26° | 175 | 18.4 | 12.2 | 2.9 |
| Oct | 32° / 24° | 43 | 4.7 | 11.4 | 4.6 |
| Nov | 30° / 19° | 38 | 2.2 | 10.8 | 6.6 |
| Dec | 26° / 15° | 14 | 1.7 | 10.5 | 8.2 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Costa Rica gets about 590 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.
The wetter season lasts 3.5 months, from around Jun 26 to Oct 11, peaking in September at about 71% chance on a given day. The drier stretch runs the rest of the year, bottoming out around May 28.
September is the wettest month by volume, with 175 mm over about 18 wet days; May is the driest, with 1 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 6 | 6 | 2 | 1 | 1 | 8 | 43 | 62 | 59 | 17 | 7 | 6 |
| Rain days | 2 | 2 | 1 | 0 | 0 | 2 | 14 | 19 | 18 | 5 | 2 | 2 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 6 | 2 |
| Feb | 6 | 2 |
| Mar | 2 | 1 |
| Apr | 1 | 0 |
| May | 1 | 0 |
| Jun | 8 | 2 |
| Jul | 43 | 14 |
| Aug | 62 | 19 |
| Sep | 59 | 18 |
| Oct | 17 | 5 |
| Nov | 7 | 2 |
| Dec | 6 | 2 |
Monthly rainfall
Over a full year, Costa Rica collects about 590 mm of rain across 66 wet days — roughly 49 mm in an average month.
It doesn’t fall evenly. September is the wettest month with 175 mm, while May is the driest at just 1 mm. The three wettest months alone bring about 76% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 13 | 14 | 3 | 1 | 1 | 14 | 108 | 168 | 175 | 43 | 38 | 14 |
| Rain days | 2 | 2 | 1 | 0 | 0 | 2 | 14 | 19 | 18 | 5 | 2 | 2 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 13 | 2 |
| Feb | 14 | 2 |
| Mar | 3 | 1 |
| Apr | 1 | 0 |
| May | 1 | 0 |
| Jun | 14 | 2 |
| Jul | 108 | 14 |
| Aug | 168 | 19 |
| Sep | 175 | 18 |
| Oct | 43 | 5 |
| Nov | 38 | 2 |
| Dec | 14 | 2 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Costa Rica, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around December 12 and lasts for 6.4 months, ending around June 25. The clearest month is May, when the sky is clear, mostly clear, or partly cloudy 86% of the time on average.
The cloudier part of the year begins around June 26 and lasts for 3.1 months, ending around September 26. The cloudiest month is August, when it is overcast or mostly cloudy 73% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 66 | 68 | 71 | 72 | 86 | 80 | 36 | 27 | 47 | 81 | 78 | 66 |
| Cloudier (%) | 34 | 32 | 29 | 28 | 14 | 20 | 64 | 73 | 53 | 19 | 22 | 34 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 66 | 34 |
| Feb | 68 | 32 |
| Mar | 71 | 29 |
| Apr | 72 | 28 |
| May | 86 | 14 |
| Jun | 80 | 20 |
| Jul | 36 | 64 |
| Aug | 27 | 73 |
| Sep | 47 | 53 |
| Oct | 81 | 19 |
| Nov | 78 | 22 |
| Dec | 66 | 34 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 6, brings about 13 h 30 min of light; the shortest, around January 1, only 10 h 30 min — a swing of roughly 3 hours.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 10.6 | 11.1 | 11.8 | 12.6 | 13.2 | 13.5 | 13.4 | 12.9 | 12.2 | 11.4 | 10.8 | 10.5 |
| Sunrise (AM) | 7:00 | 6:50 | 6:25 | 5:53 | 5:30 | 5:24 | 5:34 | 5:48 | 6:00 | 6:12 | 6:31 | 6:51 |
| Sunset (PM) | 5:38 | 5:59 | 6:14 | 6:27 | 6:41 | 6:55 | 6:57 | 6:40 | 6:08 | 5:37 | 5:18 | 5:20 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 10.6 | 7:00 | 5:38 |
| Feb | 11.1 | 6:50 | 5:59 |
| Mar | 11.8 | 6:25 | 6:14 |
| Apr | 12.6 | 5:53 | 6:27 |
| May | 13.2 | 5:30 | 6:41 |
| Jun | 13.5 | 5:24 | 6:55 |
| Jul | 13.4 | 5:34 | 6:57 |
| Aug | 12.9 | 5:48 | 6:40 |
| Sep | 12.2 | 6:00 | 6:08 |
| Oct | 11.4 | 6:12 | 5:37 |
| Nov | 10.8 | 6:31 | 5:18 |
| Dec | 10.5 | 6:51 | 5:20 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Costa Rica averages about 16 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 25 days.
The sunnier stretch runs 8.8 months, from around Sep 30 to Jun 24. The sunniest month is May, with roughly 23 sunny days (brilliant).
The greyest month is August, down near 3 sunny days — about 88% fewer than the May peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 18 | 16 | 19 | 19 | 24 | 20 | 5 | 3 | 8 | 22 | 20 | 17 |
| Sky | Bright | Bright | Bright | Bright | Brilliant | Bright | Gloomy | Gloomy | Mixed | Bright | Bright | Bright |
| Sunny days | Sky | |
|---|---|---|
| Jan | 18 | Bright |
| Feb | 16 | Bright |
| Mar | 19 | Bright |
| Apr | 19 | Bright |
| May | 24 | Brilliant |
| Jun | 20 | Bright |
| Jul | 5 | Gloomy |
| Aug | 3 | Gloomy |
| Sep | 8 | Mixed |
| Oct | 22 | Bright |
| Nov | 20 | Bright |
| Dec | 17 | Bright |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Costa Rica, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 7.3 months, from around April 19 to November 26. The muggiest month is June, when the air feels humid, muggy or worse about 100% of the time.
The most comfortable stretch runs from around November 27 to April 18, and January is the most comfortable month — the air is dry or comfortable 64% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 21 | 19 | 8 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 16 |
| Comfortable (%) | 43 | 40 | 41 | 22 | 3 | 0 | 0 | 0 | 0 | 1 | 8 | 32 |
| Humid (%) | 34 | 36 | 44 | 56 | 25 | 1 | 0 | 0 | 0 | 3 | 26 | 38 |
| Muggy (%) | 3 | 5 | 7 | 19 | 46 | 12 | 0 | 0 | 0 | 13 | 41 | 14 |
| Oppressive (%) | 0 | 0 | 0 | 1 | 25 | 61 | 14 | 0 | 3 | 32 | 20 | 0 |
| Miserable (%) | 0 | 0 | 0 | 0 | 1 | 26 | 86 | 100 | 97 | 51 | 2 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 21 | 43 | 34 | 3 | 0 | 0 |
| Feb | 19 | 40 | 36 | 5 | 0 | 0 |
| Mar | 8 | 41 | 44 | 7 | 0 | 0 |
| Apr | 2 | 22 | 56 | 19 | 1 | 0 |
| May | 0 | 3 | 25 | 46 | 25 | 1 |
| Jun | 0 | 0 | 1 | 12 | 61 | 26 |
| Jul | 0 | 0 | 0 | 0 | 14 | 86 |
| Aug | 0 | 0 | 0 | 0 | 0 | 100 |
| Sep | 0 | 0 | 0 | 0 | 3 | 97 |
| Oct | 0 | 1 | 3 | 13 | 32 | 51 |
| Nov | 2 | 8 | 26 | 41 | 20 | 2 |
| Dec | 16 | 32 | 38 | 14 | 0 | 0 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Wind in Costa Rica is steady company: average speeds sit near 8 km/h — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 8 | 8 | 8 | 8 | 8 | 9 | 7 | 7 | 7 | 7 | 7 | 7 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 8 | calm |
| Feb | 8 | calm |
| Mar | 8 | calm |
| Apr | 8 | calm |
| May | 8 | calm |
| Jun | 9 | calm |
| Jul | 7 | calm |
| Aug | 7 | calm |
| Sep | 7 | calm |
| Oct | 7 | calm |
| Nov | 7 | calm |
| Dec | 7 | calm |
Hazard calendar for Costa Rica
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Costa Rica sits in the eastern Pacific hurricane zone; the season peaks August–September.
Costa Rica's rainy season runs July–September, when most of the year's rain falls.
Best time to visit Costa Rica
To characterize how pleasant the weather is in Costa Rica throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around early April, Costa Rica is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Costa Rica for general outdoor tourist activities is from late November to mid April, with a peak score in the first week of January.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 8.4 | 8.3 | 8.2 | 6.9 | 5.7 | 4.5 | 2.9 | 2.6 | 3.0 | 4.6 | 6.6 | 8.2 |
| Rating | ideal | ideal | ideal | good | good | fair | poor | poor | poor | fair | good | ideal |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 8.4 | ideal |
| Feb | 8.3 | ideal |
| Mar | 8.2 | ideal |
| Apr | 6.9 | good |
| May | 5.7 | good |
| Jun | 4.5 | fair |
| Jul | 2.9 | poor |
| Aug | 2.6 | poor |
| Sep | 3.0 | poor |
| Oct | 4.6 | fair |
| Nov | 6.6 | good |
| Dec | 8.2 | ideal |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Costa Rica for hot-weather activities is from mid October to late June, with a peak score in the second week of April.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Costa Rica, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around July (highs near 34°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 26°C), pack light clothes.
In July, Costa Rica sees daytime highs around 34°C and nights near 26°C. Pack light clothes. Worth having: rain gear and sun protection. About 14 days see rain.
Sea temperature near Costa Rica
Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.
The sea at the nearest coast (about 34 km away) is warmest in August at about 30°C and coldest in February near 21°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) | 21 | 21 | 21 | 22 | 25 | 28 | 29 | 30 | 30 | 29 | 26 | 23 |
| Comfort | Refreshing | Refreshing | Refreshing | Refreshing | Warm | Warm | Tropical | Tropical | Tropical | Tropical | Warm | Refreshing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 21 | Refreshing |
| Feb | 21 | Refreshing |
| Mar | 21 | Refreshing |
| Apr | 22 | Refreshing |
| May | 25 | Warm |
| Jun | 28 | Warm |
| Jul | 29 | Tropical |
| Aug | 30 | Tropical |
| Sep | 30 | Tropical |
| Oct | 29 | Tropical |
| Nov | 26 | Warm |
| Dec | 23 | Refreshing |
UV index (midday) in Costa Rica by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Costa Rica peaks around May 11 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 5 (high).
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) | 5 | 8 | 10 | 12 | 12 | 11 | 12 | 11 | 10 | 8 | 6 | 5 |
| Level | High | Very high | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | High | High |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 5 | High |
| Feb | 8 | Very high |
| Mar | 10 | Very high |
| Apr | 12 | Extreme |
| May | 12 | Extreme |
| Jun | 11 | Extreme |
| Jul | 12 | Extreme |
| Aug | 11 | Extreme |
| Sep | 10 | Extreme |
| Oct | 8 | Very high |
| Nov | 6 | High |
| Dec | 5 | High |
Average hourly UV index in Costa Rica
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in May the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 5 | 6 | 7.5 | 8 | 8.5 | 8.5 | 8.5 | 8 | 7.5 | 6.5 | 5.5 | 5 |
| UV ≥ 6 (h/day) | 0 | 3.5 | 5 | 6 | 6 | 6 | 6.5 | 6 | 5.5 | 4 | 0 | 0 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 5 | 0 |
| Feb | 6 | 3.5 |
| Mar | 7.5 | 5 |
| Apr | 8 | 6 |
| May | 8.5 | 6 |
| Jun | 8.5 | 6 |
| Jul | 8.5 | 6.5 |
| Aug | 8 | 6 |
| Sep | 7.5 | 5.5 |
| Oct | 6.5 | 4 |
| Nov | 5.5 | 0 |
| Dec | 5 | 0 |
Air quality in Costa Rica by month
Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.
Air quality in Costa Rica is worst in May — around 43 µg/m³ PM2.5 (poor), about 3.9× the cleanest month (January, 11 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 11 | 11 | 13 | 18 | 43 | 23 | 17 | 12 | 13 | 13 | 11 | 11 |
| Level | Good | Good | Moderate | Moderate | Poor | Moderate | Moderate | Good | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 11 | Good |
| Feb | 11 | Good |
| Mar | 13 | Moderate |
| Apr | 18 | Moderate |
| May | 43 | Poor |
| Jun | 23 | Moderate |
| Jul | 17 | Moderate |
| Aug | 12 | Good |
| Sep | 13 | Moderate |
| Oct | 13 | Moderate |
| Nov | 11 | Good |
| Dec | 11 | Good |
Growing season
Costa Rica is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Costa Rica banks about 5,566 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 306 | 295 | 363 | 406 | 498 | 565 | 618 | 611 | 579 | 558 | 430 | 336 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 306 |
| Feb | 295 |
| Mar | 363 |
| Apr | 406 |
| May | 498 |
| Jun | 565 |
| Jul | 618 |
| Aug | 611 |
| Sep | 579 |
| Oct | 558 |
| Nov | 430 |
| Dec | 336 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Costa Rica receives about 5.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.1 and 7.8 kWh/m².
The brighter stretch of the year lasts 5.1 months, from around Feb 25 to Jul 28. The brightest month is May, averaging about 7.8 kWh/m² (intense).
The dimmest month is December, down near 4.1 kWh/m² — roughly 47% less than the May peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.4 | 5.3 | 6.5 | 7.4 | 7.8 | 7.1 | 6.0 | 5.4 | 5.0 | 5.3 | 4.6 | 4.1 |
| Level | Bright | Bright | Intense | Intense | Intense | Intense | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 4.4 | Bright |
| Feb | 5.3 | Bright |
| Mar | 6.5 | Intense |
| Apr | 7.4 | Intense |
| May | 7.8 | Intense |
| Jun | 7.1 | Intense |
| Jul | 6.0 | Bright |
| Aug | 5.4 | Bright |
| Sep | 5.0 | Bright |
| Oct | 5.3 | Bright |
| Nov | 4.6 | Bright |
| Dec | 4.1 | Bright |
Where is Costa Rica?
Costa Rica sits at 24.6°N, 107.4°W, 30 m above sea level, in Mexico. The nearest listed city is Licenciado Benito Juárez, 17 km away.
Topography around Costa Rica
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Costa Rica.
Within 3 km, the terrain around Costa Rica has only modest variations in elevation — a maximum elevation change of 21 m around an average of 25 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 401 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,932 m.
The land around Costa Rica is covered by cropland (64%) within 3 km, cropland (62%) within 16 km, and trees (39%), water (27%) and cropland (20%) within 80 km.
Mexico travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type A / B
- 120 / 127 V · 60 Hz
- Prices
- ≈ 54% of US
- price level, 2025
- GDP per capita
- $13,889
- 2025
- Happiness
- 7.0 / 10
- World Happiness, 2025
- Safe drinking water
- 43%
- of population, 2024
- Homicide rate
- 24.9
- per 100k, 2023
- Road deaths
- 12.8
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Very low
- EF EPI 440
- 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 Costa Rica (24.5907°, -107.3899°, elevation 30 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).