Weather in San Luis Potosí in December

Prime time. If you get to pick your dates, December is the one. Highs average 21.8 °C, lows 6.9 °C, and rain falls on 1 days — nothing in the month is working against you.

December is the highest-scoring month of the twelve. The nearest rival is January, and the month at the other end of the year is June.

Rain falls on only 1 days, so an itinerary with no wet-weather fallback is a reasonable risk. 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 December reaches 30 °C. Across the twenty years measured, the hottest December day reached 26.9 °C and the coldest night fell to -3.9 °C.

December is dependably dry, and that reliability is the point: across the twenty years measured, the wettest December on record still only managed 32 mm, and the driest managed 0 mm. There is no meaningful variability to plan around, which makes this one of the few months anywhere that you can build a fixed outdoor itinerary against without a fallback. The wettest single day in twenty years of Decembers brought 15 mm. Rain simply is not the variable that decides this trip — heat, crowds and cost are.

Wind is light at 9.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 61%.

How December sits in the year

Temperatures hold steady either side: 23 °C in November, 21.8 here, 21.3 in January. Nothing about the timing within the month matters much.

Daylight in December

December sits at the dark end of San Luis Potosí's year — 10.8 hours of daylight against 13.5 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

Despite being inland, the year stays fairly even: 24.5 °C between the year's warmest afternoons and coldest nights. At 1886 m, altitude is doing as much work here as latitude: thinner air means fierce sun by day and heat that leaves the moment it sets. Within December itself the daily swing is 14.9 °C, so mornings and afternoons need different clothes.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, April is the trade worth considering — 14 points weaker on weather, and materially quieter.

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

December in San Luis Potosí versus nearby

If San Luis Potosí is one option among several, the nearby comparison is worth making. Santiago de Querétaro is close enough to be a coin toss — 2 °C warmer, the same number of rain days. Morelia is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: December is the answer for San Luis Potosí. If it is booked out or priced out, January is the next best thing at 1 points behind, and June is the month to keep off the shortlist.

Every month in San Luis Potosí

See all twelve months in San Luis Potosí, or where else to go in December.