Weather in Monterrey in May

A hard month. May is a hard month in Monterrey, and worth planning around. Daytime highs average 37.1 °C and the afternoon is not negotiable — outdoor plans move to early morning or evening.

May ranks 11 of 12 — near the bottom of Monterrey's year. January is the month that works, and the swing between the two is 59 points, which is a different holiday rather than a slightly better one.

Rain on 10 days, 1 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for heat management rather than style: shade, water, and a schedule that gives up on the middle of the day.

What the averages hide

Averages flatten a month, and this one hides a few things: 23 days of the month clear 35 °C — that is not a heatwave, it is the month; the day swings 15.4 °C from low to high, which means one bag has to cover both. Across the twenty years measured, the hottest May day reached 45.7 °C and the coldest night fell to 9.5 °C.

May is moderately variable: 3 mm in the driest year against 102 mm in the wettest, around an average of 44 mm. Roughly two Mays in three land near that average, and the third does something else entirely.

Wind is light at 9.8 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 54%.

How May sits in the year

Temperatures hold steady either side: 35.8 °C in April, 37.1 here, 37 in June. Nothing about the timing within the month matters much. Rain has already shifted: 5 days more than April had.

Daylight in May

May is at or near the longest days of Monterrey's year: 13.4 hours of daylight, gaining 0.5 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

An inland climate

With no coast nearby, the year swings a fair way — 25.7 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. Within May itself the daily swing is 15.4 °C, so mornings and afternoons need different clothes.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

May in Monterrey versus nearby

If Monterrey is one option among several, the nearby comparison is worth making. Laredo is close enough to be a coin toss — within a degree on temperature, 2 days less rain. Brownsville is a better bet in May — 4.4 °C cooler, 4 days less rain.

So: May is a compromise. January is 57 points better and is what Monterrey is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Monterrey

See all twelve months in Monterrey, or where else to go in May.