AU
Level 2Exercise increased caution
Exercise increased caution
Costa Rica · Month guide
Costa Rica in September
Around 27 °C with 363 mm of rain and 4.1 hours of sun a day.
September is a challenging month for Costa Rica overall; regional choices matter most. Around 27 °C with 363 mm of rain and 4.1 hours of sun a day. Use the regional grid below to find where this month works best — national averages hide the swings between coast, highlands, and inland.
Avoid
Costa Rica · September
What the weather usually does
Costa Rica · typical month
- Day / night21 – 27 °CYear range 20 – 28 °C
- Rainfall364 mmYear range 66 – 508 mm
- Sunshine4.1 hr / dayYear range 3.5 – 7.8 hr / day
What’s open · September
Things to do in Costa Rica in September
Nothing in Costa Rica shuts for the season, and 2 things below are at their best in September.
- At its bestGreen turtle nesting, Tortuguero
green turtles nest from July to mid-October, with the peak through August and September
Sources: tortugueroinfo.com, costaricaexperts.com
- At its bestOlive ridley arribada, Ostional
the largest arrivals of the year, peaking in October in the depths of the rainy season
Sources: gypsycabnosara.com, costaricaexperts.com
Opening seasons are checked by hand against the operators and parks themselves, not derived from the climate figures on this page. Last reviewed 2026-08-28. Dates move — confirm before you book.
Safety · 6 governments
What the governments say about Costa Rica
Combined advisory · most-cautious-wins
Exercise increased caution
Highest level across 6 governments · Advisory last changed
See breakdown by countryHide breakdown
CA
Level 2Exercise increased caution
Exercise increased caution
DE
Level 1Exercise normal precautions
Exercise normal precautions
NL
Level 2Exercise increased caution
Exercise increased caution
UK
Level 1Exercise normal precautions
Exercise normal precautions
US
Level 2Exercise increased caution
Exercise increased caution
Climate at a glance · 10-year ERA5
A decade of weather, in one page
— daytime high— overnight low▬ typical range
View data table
| Month | Average daytime high (°C) | Average overnight low (°C) | Typical low | Typical high |
|---|---|---|---|---|
| January | 26.1 | 19.7 | 18.2 | 27.6 |
| February | 26.6 | 19.9 | 18.4 | 28.1 |
| March | 27.4 | 20.2 | 18.7 | 29.0 |
| April | 27.9 | 21.0 | 19.6 | 29.4 |
| May | 27.9 | 21.7 | 20.6 | 29.7 |
| June | 27.2 | 21.5 | 20.4 | 28.7 |
| July | 27.0 | 21.4 | 20.4 | 28.4 |
| August | 27.2 | 21.2 | 20.3 | 28.8 |
| September | 27.3 | 21.1 | 20.3 | 28.7 |
| October | 26.8 | 20.9 | 20.1 | 28.1 |
| November | 26.1 | 20.8 | 19.7 | 27.6 |
| December | 26.0 | 20.2 | 18.8 | 27.3 |
View data table
| Month | Rainfall (mm) |
|---|---|
| January | 107 |
| February | 72 |
| March | 66 |
| April | 145 |
| May | 355 |
| June | 402 |
| July | 347 |
| August | 370 |
| September | 364 |
| October | 508 |
| November | 418 |
| December | 188 |
View data table
| Month | Sunshine hours (hr / day) |
|---|---|
| January | 6.9 |
| February | 7.7 |
| March | 7.8 |
| April | 6.5 |
| May | 4.3 |
| June | 3.5 |
| July | 3.6 |
| August | 4.0 |
| September | 4.1 |
| October | 3.6 |
| November | 3.8 |
| December | 5.9 |
— average▬ typical range
View data table
| Month | Average wind speed (km/h) | Typical low | Typical high |
|---|---|---|---|
| January | 8.4 | 5.5 | 11.8 |
| February | 9.0 | 5.3 | 12.5 |
| March | 8.3 | 5.1 | 11.2 |
| April | 6.7 | 4.3 | 10.0 |
| May | 5.2 | 3.7 | 7.5 |
| June | 5.0 | 3.7 | 6.8 |
| July | 6.0 | 4.2 | 8.2 |
| August | 5.3 | 3.8 | 7.3 |
| September | 4.7 | 3.7 | 5.9 |
| October | 4.8 | 3.8 | 6.4 |
| November | 5.8 | 4.1 | 7.9 |
| December | 7.4 | 4.8 | 10.1 |
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Sea surface temperature
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Heat index
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Humidity
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