San José Future Trends
Costa Rica · North America · Trend-based projections to 2050
This page projects San José's weather to 2030, 2040 and 2050, fitting one trend line per variable to its own 50-year ERA5 record. Around it sits a statistical range: temperature, tropical days and frost days get a Best and Worst scenario; precipitation and sunshine hours get a Low and High estimate instead, since more or less rain or sun isn't inherently better or worse. An R² score shows how closely the trend fits the record, so a lower R² means more year-to-year noise. Which variable in San José shifts hardest, and how firmly the record backs that line, is laid out per trajectory below.
Data through August 16, 2026.
Climate Change Practical
What it means at home20 everyday facts per capital, from solar panel losses to insect season,…
Climate Transition
Ranked by pace of changeEvery live world capital ranked by how fast its own weather record is shifting,…
Meteo Capital Cities
Records and extremesHistorical weather for 195 world capitals: temperature, wind, rain and sunshine…
Climate Capitals Trends
50 years of change50 years of temperature and precipitation history for nearly 200 world…
Capital Climate Atlas
All five toolsOne home for all five INZIU weather and climate tools, built on the same 50…
Frequently asked questions about San José's projected trends
How warm will San José be in 2050?
Extrapolated from San José's own record since 1976, the average daytime high in 2050 works out at roughly 25.3°C, down 0.4°C from 2025. This is a straight-line projection of measured weather data, not a climate model or a scenario-based forecast.
How certain is the temperature projection for San José?
The 2050 range runs from 24.9°C to 25.7°C. That spread comes from the 95% confidence interval on the trend line's own slope, so the noisier San José's record, the wider the band. The trend accounts for 23% of the variation between years; the rest is ordinary year-to-year swing.
How many days above 30°C will San José get in 2050?
The trend line lands on roughly 1 day above 30°C a year in 2050, against 0 in 2025. These are the days that set peak cooling demand, so this figure matters more for grid planning and building design than the annual average above.
Will San José still get frost in 2050?
San José already recorded no frost days in 2025, and the trend line does not change that. Frost is not a useful measure here, though the heat figures above are.
Is San José getting wetter or drier by 2050?
The trend line lands on roughly 3428mm of precipitation a year in 2050, against 2666mm in 2025, so wetter. An annual total says little about distribution though: the same rainfall can arrive in shorter, harder bursts, and that is what loads drains and water storage.
Will San José get more sunshine by 2050?
The trend line lands on roughly 3343 sunshine hours a year in 2050, against 3323 in 2025, so more sun. Sunshine hours bear directly on rooftop solar yield, though heat works against it at the same time: a panel loses efficiency at high temperatures.
