San José in September
In September, San José averages 26°C (79°F) during the day and 17°C (63°F) at night, with frequent rain — about 24 days of the month see precipitation (305 mm total).
ShoulderConditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.
September offers comfortable temperatures in San José, with some rain to plan around.
How September compares to the rest of the year in San José
September is in the middle of the year for warmth in San José (6th of 12) and one of the wettest months (2nd of 12). Daytime temperature runs 1°C above the annual average (25°C). September runs roughly the same as August (26°C) and cools 1°C in October (25°C).
September sunrise & sunset in San José
Times shown for San José local time (America/Costa_Rica), calculated for the 15th of September. They shift by a few minutes day to day across the month.
Photography light in San José — September
Golden-hour and blue-hour windows for the 15th of September, in San José's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — San José in September
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on September's tier (Shoulder) and San José's popularity.
Crowds & pricing — September in San José
San José is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.
Why this tier: comfortable tourism weather
Sun & mosquito risk — September in San José
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
San José in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 24°C / 75°F | 15°C / 59°F | 6 mm | 1 | — |
| February | 25°C / 77°F | 15°C / 59°F | 8 mm | 1 | — |
| March | 26°C / 79°F | 16°C / 61°F | 18 mm | 2 | — |
| April | 27°C / 81°F | 17°C / 63°F | 65 mm | 7 | — |
| May | 26°C / 79°F | 17°C / 63°F | 226 mm | 19 | — |
| June | 26°C / 79°F | 17°C / 63°F | 248 mm | 22 | — |
| July | 25°C / 77°F | 17°C / 63°F | 211 mm | 21 | — |
| August | 26°C / 79°F | 17°C / 63°F | 241 mm | 23 | — |
| September | 26°C / 79°F | 17°C / 63°F | 305 mm | 24 | — |
| October | 25°C / 77°F | 17°C / 63°F | 300 mm | 25 | — |
| November | 25°C / 77°F | 16°C / 61°F | 145 mm | 14 | — |
| December | 24°C / 75°F | 15°C / 59°F | 41 mm | 4 | — |
Other cities with similar September weather
🌍 See the full ranked list of climate twins for San José in September →
Frequently asked questions
How hot is San José in September?
In September, San José averages a high of 26°C (79°F) and a low of 17°C (63°F) — generally warm.
Does it rain a lot in San José in September?
September is quite rainy in San José, with about 24 rainy days on average.
Is September a good time to visit San José?
September is warm but on the rainy side. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for San José in September?
Pack light layers for warm days and cooler evenings, plus a compact umbrella or rain jacket. See the full September packing list for San José for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.