Fortuna Temperature by Month

The average annual maximum temperature in Fortuna, Alajuela, Costa Rica is 30°C (86°F), with little variation between seasons. This page covers monthly averages, day-night differences, and how Fortuna compares to cities worldwide.

In Fortuna temperatures are generally consistent throughout the year. Maximum daytime temperatures range from a comfortable 29°C (84°F) in December to a very warm 32°C (90°F) in April. Nighttime lows range from 22°C (72°F) in April to 21°C (70°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Fortuna by month:

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. April, the warmest month, averages 265 hours of sunshine.

The chart below shows the average temperature throughout the year:

Fortuna's average annual maximum temperature is 30°C (86°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

Osaka, Japan averages 22°C (72°F) annually, with hot humid summers, mild winters, and pleasant spring and autumn seasons.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Fortuna, December is the coolest month, with average highs of 29°C (84°F) and humidity around 72%, considered high. In April, the warmest month, temperatures average 32°C (90°F) with 62% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.

Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.

For more on Fortuna's weather, including monthly rainfall, sunshine hours, and humidity, visit our Fortuna climate page.