Fortuna Weather in September
Fortuna in September sees high daytime temperatures of 29°C (84°F) and nighttime lows of 21°C (70°F). As part of the rainy season, showers are frequent and often heavy. Budget around 308 mm (12 in) of rainfall for the month.
Rainfall in Fortuna in September
As part of the rainy season, Fortuna sees around 23 days of rain in September, with an average of 308 mm (12 in). Rainfall this month is frequent and tends to be fairly heavy when it does fall. Packing waterproofs is a good idea.
Temperature in Fortuna in September
Daytime highs in Fortuna in September reach 29°C (84°F), with nights around 21°C (70°F). Overall, the month follows a fairly predictable daily temperature pattern. Nights remain mild at 21°C (70°F), making evenings a pleasant time to be outdoors.
Sunshine in Fortuna in September
The city usually sees around 159 hours of sunlight, indicating a moderately sunny period (despite it being part of rainy season).If you prefer dry days with pleasant temperatures, September may not be the ideal month to visit Fortuna. Our weather planner can help you explore destinations with more pleasant weather conditions.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Costa Rica, check out our Fortuna's climate page.
Fortuna Temperature in September
Min Temperature
21°C (70°F)
Max Temperature
29°C (84°F)
Chance of Rain
77%
Precipitation
308 mm (12 in)
Rainy days
23 days
Sunshine
159 hours *
Percentage Sunshine
*
Daily Historical Temperatures
44-year average (1976-2025)
Based on our historical records, temperatures in Fortuna typically stay consistent throughout September, with daily highs averaging around 29°C (84°F). Nights are pleasant, with lows around 19°C (66°F).
Average temperatures in September
Daily Historical Precipitation
44-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Fortuna in September
Browse day-by-day weather records for Fortuna spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Fortuna historical weather extremes in September
Based on 29 years of weather observations in Fortuna between 1996 and 2025, these are the recorded extremes.
- The hottest September day on record in Fortuna reached 33°C (91°F) (September 5, 1997).
- The coldest September day was on September 29, 2010, with a maximum of 21°C (70°F).
- Nighttime temperatures dropped to 11°C (52°F) on September 30, 2012, marking the coldest September night on record.
- The wettest day in September Fortuna was on September 27, 2019 with 171 mm (6.7 in) of precipitation.
Best Places in Costa Rica in September
Find out more about the weather in Costa Rica and which places have the best travel conditions in this month. See all of Costa Rica in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Fortuna in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.What To Do in Fortuna in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Costa Rica, check out our Fortuna's climate page.
See the full Fortuna climate overview or explore weather in Costa Rica.
