On the evening of September 14, children in San Jose walk the streets holding paper lanterns, the faroles, and the sound of school drums carries from block to block. By morning the city is hung with blue, white and red flags, and the bands are out again. September is the heart of the green season in the capital, a month of cool mornings, afternoon downpours and a national holiday that fills the center with music.
What is the weather like in San Jose in September?
San Jose in September brings gentle, damp weather, featuring mild starts to the day, chilly nights, and showers on nearly every date.
| Month | Average high (°F) | Average low (°F) | Rain days |
|---|---|---|---|
| August | 75.4 | 64.2 | 23.9 |
| September | 75.3 | 63.8 | 26.2 |
| October | 74.4 | 63.8 | 26.8 |
At roughly 3,800 feet, the Central Valley keeps its spring-like air even in the rainy months. Mornings are often the best part of the day, with a bright, washed light over the surrounding mountains and enough warmth to sit outside with a coffee. By late morning the clouds typically gather, and the rain generally shows up in the afternoon or early evening, falling at times as a brief shower and at other times as a steady downpour lasting for hours.
A few days in the month bring heavy rain, so plan your outdoor time before lunch and keep the late afternoon for museums, cafés and long meals. Once the sun sets, evenings turn cool enough for a light sweater, and with days lasting close to twelve hours, a full morning outdoors is easy to fit in.
Dress in layers and bring a real rain jacket, since an umbrella struggles against the wind that comes with the heavier storms. Do not count on a clear view of the volcanoes around the valley, because clouds often sit on the summits by midday. San Jose sits away from the coast, so no ocean lies here, yet the rain can still come down hard and might make traffic crawl throughout the city.
What to do in San Jose in September
The big date of the month is September 15, Independence Day, and the celebration begins the night before. On the evening of September 14 the Desfile de Faroles sends children through town with paper lanterns, a gentle, glowing procession that families often follow on foot. The next morning brings school bands, drums, flags and uniforms, and the center feels like one long street party.
Outside the holiday, September is a good month for the indoor and covered pleasures of the capital. The rain makes the cafés and markets feel even more inviting, and the lower crowds make for easy wandering. Plan your walking for the morning, and let the showers decide the rest of the day.
The Central Market and the taste of a casado
For an authentic sample of Costa Rican cuisine, head to the Central Market, one vast landmark beneath a single roof that unites food stalls, coffee vendors, souvenir shops and little lunch counters. Rain is no problem here, since you are under a roof the whole time. The narrow aisles fill with the smell of roasting coffee, grilled meat and ripe fruit.
Grab a seat at the counter and ask for a casado, the country’s midday meal of rice, beans, plantain, and salad, plus whichever meat or fish you choose. Add a glass of fresh fruit juice, and save room for something sweet from one of the bakery stands. Try one of the lunch counters, and take souvenirs and coffee beans home afterward.
The market suits almost every traveler, including families and anyone who wants to try local flavors without a long restaurant meal. Keep your bag zipped and close to you, as in any crowded place, since petty crime is common across Costa Rica.
Independence Day in the streets
The center of the capital is where the holiday is most visible, with flags on balconies, bands marching and families gathering along the route. The mood is proud and friendly, and it is easy to join the crowd as a spectator. The lantern walk on the evening of the 14th is the gentlest part, with children holding up their faroles in the dark.
Arrive early on the 15th to find a spot with a view, and bring a rain jacket in case an afternoon shower sweeps through. Plan meals and errands with the holiday in mind. The celebration suits families, photographers and anyone curious about how Costa Ricans mark the national day.
Coffee, museums and rainy-afternoon plans
September rain is a good excuse to settle into a café and drink the coffee the Central Valley is known for. Order it prepared at the table in a pour-over, and pair it with a pastry. The slow pace of a wet afternoon fits the habit well.
The city’s Pre-Columbian Gold Museum, Jade Museum and National Museum make strong rain-day stops. Use the dry morning for the walking, and keep the museum or the café for when the clouds close in. Check each site’s hours and fees before you go.
Evenings are best spent over dinner in a neighborhood restaurant. The State Department rates Costa Rica Level 2, exercise increased caution, due to crime, and petty crime is common throughout the country.
A two-day itinerary for San Jose in September
Day 1 starts early, because the morning is when the sky is most likely to be clear. Begin with a coffee and a walk through the center, taking in the flags and the early bustle if the holiday is near. By midday, head to the Central Market for a casado and fresh fruit, a lunch that keeps you under cover as the clouds gather.
In the afternoon, when the rain usually arrives, move to a museum or a café and let the shower pass. When evening comes, eat at a restaurant in a local neighborhood, and take a taxi once it is dark. If you are here on September 14, spend the evening watching the lantern parade, then call it a night.
Day 2 gives you a slower pace, built around the holiday if the dates line up. On the morning of the 15th, find a place along the parade route for the school bands and flags, with a rain jacket in your bag. With just over twelve hours of daylight, you can take your time and beat the crowds.
Spend the afternoon at the National Theatre or the Jade Museum, then linger over coffee while the rain falls. If the weather clears, take a short walk through a different neighborhood before dinner. Save the evening for a last meal of local dishes, and keep the rain card handy: indoor markets, galleries and cafés are never far away.
Is San Jose busy in September?
San Jose is fairly quiet in September, apart from the days around Independence Day, when the center fills with families and parade-goers.
Most visitors land at the airport and move on within a day or two, so the capital never feels crowded with tourists in the green season. Rooms are generally easier to find than in the dry months. The exception is the holiday itself, when hotels near the parade route and popular restaurants can fill, so book those earlier than you would for an ordinary weekday.
Rental cars are usually easy to arrange in a quiet month, though it is a good habit to reserve ahead anyway. When a national park outside the city is part of your trip, look at that park’s official page for the rules in effect now. Early booking suits the holiday week, and a looser plan works fine for the rest of the month.
What to pack for San Jose in September
Bring layers for pleasant daytime weather, chilly nights and showers that may show up at any point in the afternoon.
- A real rain jacket, because afternoon downpours are common and can be heavy.
- A light sweater or fleece for evenings, when the valley air cools off.
- Shoes that repel water and hold traction well on slick pavement and stone streets.
- A small daypack with a zipper, since petty crime is common in crowded places.
- A compact umbrella for short showers between stops.
- Your passport, valid for your whole stay, and your return or onward ticket.
Good to know before you go
The U.S. State Department rates Costa Rica Level 2, ‘Exercise increased caution,’ due to crime; it says petty crime is common throughout Costa Rica and that violent crime also affects tourists, including armed robbery, homicide and sexual assault.
September falls in the green season, and the rain comes most afternoons, so plan outdoor time for the morning. Around Independence Day, expect parade crowds, some changed business hours and slower traffic in the center.
A passport valid for the entire length of your stay is required, along with proof of onward travel to another country or a return ticket. It might be possible to remain for as many as 180 days with no visa, as decided by officials, though you should not count on it.
San Jose in September vs August and October
Moving the trip to August changes little. You still get cool mornings and afternoon showers since the rain is slightly lighter and the temperatures are almost the same. What you lose is Independence Day, the lantern walk and the parade, which are the best reasons to be in the capital in September.
October is a touch cooler and wetter, with rain on most days, so the afternoons can feel gloomier and outdoor plans need more flexibility. The national holiday has passed by then, and the streets return to their ordinary rhythm. Travelers who dislike heavy rain may find October the more demanding of the three months.
If the holiday matters to you, choose September and plan for mid-month. If you want the quietest, simplest trip and do not mind missing the parade, August works just as well. Anyone who is flexible about weather and wants an easygoing capital can pick October.
Is September a good time to visit San Jose?
September works well for visitors drawn to hometown traditions, roofed market halls and a capital with less bustle, and who take the rain as simply part of the experience.
It suits food lovers, families who like a parade and anyone using San Jose as a first stop before heading on. Travelers hoping for assured sunny days or unobstructed volcano vistas might find it a poorer match, and they could favor the months with less rain. On arrival, start with a casado at the Central Market, then keep the afternoon flexible for the rain. What sets this month apart is the night of September 14, when children walk through the dark streets with their paper lanterns and the capital turns soft and glowing for a few hours.
Sources
- Open-Meteo / ECMWF ERA5, normals 1991-2020 computed for the grid cell at 9.9281N 84.0907W, checked October 8, 2026
- sunrise-sunset.org, sunrise and sunset calculated for the 15th of the month, checked October 8, 2026
- U.S. Department of State, Costa Rica Travel Advisory, issued April 1, 2026 (https://travel.state.gov/content/travel/en/traveladvisories/traveladvisories/costa-rica-travel-advisory.html), read via the State Department open data API on October 8, 2026
- U.S. Department of State, Costa Rica Travel Information, Entry and exit requirements (https://travel.state.gov/content/travel/en/international-travel/International-Travel-Country-Information-Pages/CostaRica.html), checked October 8, 2026