Weather in San José in January

Prime time. If you get to pick your dates, January is the one. Highs average 24.4 °C, lows 16 °C, and rain falls on 9 days — nothing in the month is working against you.

January ranks 3 of 12 in San José. Only February scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 9 days, 1 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average January reaches 30 °C. Across the twenty years measured, the hottest January day reached 28.2 °C and the coldest night fell to 13 °C.

January is moderately variable: 7 mm in the driest year against 129 mm in the wettest, around an average of 38 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 2.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 79%, high enough to notice on the warm days without dominating them.

How January sits in the year

Temperatures hold steady either side: 23.7 °C in December, 24.4 here, 26 in February. Nothing about the timing within the month matters much. Rain has already shifted: 5 days fewer than December had.

Daylight in January

San José sits close enough to the equator that daylight barely moves all year — 11.6 hours in January, against a range of just 1.2 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

An inland climate

Despite being inland, the year stays fairly even: 12 °C between the year's warmest afternoons and coldest nights. At 1133 m the air is thin enough to matter — sun that burns faster than the temperature suggests, and nights that cool off quickly.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in San José versus nearby

If San José is one option among several, the nearby comparison is worth making. San Isidro is the weaker option in January — 2 °C warmer, 4 days more rain. Puntarenas is the weaker option in January — 8.1 °C warmer, 5 days less rain.

So: January is effectively as good as it gets here — 5 points behind February, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in San José

See all twelve months in San José, or where else to go in January.