WeatherJourney.com

Monterrey weather by month: averages, rainfall & climate trends

Monterrey bakes at the foot of the Sierra Madre in northern Mexico, one of the country's hottest cities, and one repeatedly battered by the floods that hurricanes drag in off the Gulf. Monterrey weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−2.8°Chigh below average

24° / 12°Today
26° / 17°Average
see today in detail →

How it's changed

+1.8°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–491frost days a year now (2016–2025) · 1 in the 1940sfrost days a year · 1 in the 1940s179days above 30°C a year now (2016–2025) · 122 in the 1940sdays above 30°C · 122 in the 1940s+1.8°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 40 mmhigh 20°low 9°February, rain 38 mmhigh 23°low 11°March, rain 42 mmhigh 26°low 14°April, rain 52 mmhigh 29°low 17°May, rain 62 mmhigh 31°low 20°June, rain 45 mmhigh 33°low 22°July, rain 34 mmhigh 34°low 22°August, rain 41 mmhigh 34°low 22°September, rain 110 mmhigh 30°low 21°October, rain 69 mmhigh 27°low 17°November, rain 40 mmhigh 24°low 13°December, rain 36 mmhigh 21°low 10°wettest month September, 110 mm · 610 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Clear

Right now

13.2°

12°feels like
68%humidity
7°dew point
5 km/hfrom NW
UV index0.0
sunrise06:42sunset18:10day length11h 28m
TodayClear24°12°
TueClear24°17°
WedMostly clear28°20°
ThuClear28°20°
FriDrizzle22°20°
SatOvercast22°19°
SunDrizzle22°18°

On this date: October 19

Today (forecast)
24° / 12°
Average for October 19
26° / 17°

High below average · −2.8°C

  • Highest since 1940: 33.9° · 2012
  • Lowest since 1940: 8.9° · 1948
  • One year ago: 32° / 21°

Every October 19 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 19 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Monterrey is sampled from the ECMWF ERA5 reanalysis at 25.68°N, 100.32°W, with daily records since 1940.

Coordinates
25.68°N, 100.32°W
Time zone
America/Monterrey
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

25 of the last 31 days were warmer than the historical average for that date. Average difference: +2.3°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

Monterrey sits in northeastern Mexico, just north of the foothills of the Sierra Madre Oriental, whose peaks loom over the city. A little above 500 metres, with a hot semi-arid climate (Köppen BSh), it ranks among the hottest major cities in the country: summers are long and scorching, and even winter days can spike unexpectedly warm. Rain is scarce through winter and picks up between May and September.

The mountains that frame the city also concentrate its disasters. When Gulf hurricanes reach the Sierra Madre, they can dump staggering amounts of rain on Monterrey. Hurricane Gilbert in 1988 caused catastrophic flooding and heavy loss of life, and Hurricane Alex in 2010 unloaded a record deluge that became the worst natural disaster in the city's history. Snow is a rarity, last seen in February 2021.

August brings the year's peak warmth, with afternoons typically reaching 33.6°C and nights around 22.3°C. Around 160 nights a year stay above 20°C. The coolest month is January, when afternoons reach about 20.2°C and overnight lows sit around 8.9°C.

In total, Monterrey averages about 610 mm of precipitation a year; September is usually the wettest month (110 mm) and July the driest (34 mm).

Over the full record (since 1940), the annual mean temperature in Monterrey has risen by 1.8°C between its first decade and its last. Days above 30°C have grown noticeably more frequent, from around 120 a year in the first decade to about 180 in the last.

Sources:en.wikipedia.orgbritannica.com

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 14°C. Wettest month: September (~110 mm). Whole year averages ~610 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 61 rainy days a year: most in September (~8), fewest in July (~3).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Monterrey month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January20.2°8.9°40 mm510.6 h33.1° (2017)−6.4° (1949)
February22.7°10.7°38 mm511.1 h38.3° (2009)−5.7° (1951)
March26.3°13.8°42 mm511.8 h39.2° (1954)1.0° (1980)
April29.4°17.2°52 mm612.6 h41.3° (2011)3.4° (2007)
May31.3°20.1°62 mm713.3 h42.3° (2024)10.6° (2013)
June33.0°21.8°45 mm413.6 h43.3° (1957)14.8° (1984)
July33.6°22.2°34 mm313.5 h40.2° (1998)16.9° (1974)
August33.6°22.3°41 mm412.9 h39.8° (2013)17.0° (1961)
September30.5°20.7°110 mm812.1 h39.6° (2011)10.3° (1948)
October27.3°17.3°69 mm611.4 h37.7° (2007)3.7° (1993)
November23.6°13.0°40 mm510.7 h35.1° (2025)0.3° (2018)
December20.9°10.0°36 mm410.4 h33.4° (1955)−7.2° (1983)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.8°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.19°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Mar–May is warming fastest: +0.25°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 121.6 early in the record → 178.6 recently. Frost days: 1 → 1.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 1957, coldest in 1983: 43.3°C / −7.2°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~610 mm/year on average. Last decade: −12% vs that average. Long-term trend: +1 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Monterrey

Which is the warmest month in Monterrey?
On long-term average, the warmest month in Monterrey is August (mean daily temperature of about 27.7°C) and the coolest is January (about 13.6°C).
How does today's temperature in Monterrey compare to the historical average?
On October 19, 2026, Monterrey is forecast to reach a high of 23.6°C and a low of 12.1°C. The long-term average for this date (the full record since 1940) is a high of 26.4°C and a low of 16.5°C, so today's high is 2.8°C cooler than that average.
How much has Monterrey warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Monterrey is about 1.8°C warmer.
How much does it rain in Monterrey?
Monterrey receives about 610 mm of precipitation per year on long-term average, with September typically the wettest month.
What is the average temperature in Monterrey?
Over the full record (since 1940), the annual mean temperature in Monterrey is about 21.5°C. The warmest month is August and the coolest is January.
What are the average temperatures in Monterrey by month?
Average daily highs and lows for each month in Monterrey (°C, full record since 1940): January 20°/9°, February 23°/11°, March 26°/14°, April 29°/17°, May 31°/20°, June 33°/22°, July 34°/22°, August 34°/22°, September 30°/21°, October 27°/17°, November 24°/13°, December 21°/10°.
What is the weather like in Monterrey in summer?
June to August is summer in Monterrey, and it is hot. Afternoons run 33–34°C and nights 22°C; July is the warmest month. Rain is steady at around 40 mm a month, spread over roughly 4 days.
What is the weather like in Monterrey in winter?
Winter in Monterrey (December to February) is mild. Expect 20–23°C by day and 9–11°C at night, with January the coldest month. Rain falls on about 5 days a month, adding up to around 38 mm.
What is the weather like in Monterrey in spring?
Spring in Monterrey (March to May) is warm. It warms from 26°C by day and 14°C at night in March to 31°C and 20°C in May. Rain is steady at around 52 mm a month, spread over roughly 6 days.
What is the weather like in Monterrey in autumn?
In autumn, September through November, Monterrey is warm. September is still 30°C by day and 21°C at night; by November it is down to 24°C and 13°C. Rain eases through the season: 8 rainy days and 110 mm in September, 5 days and 40 mm in November. No season is wetter.
How many days a year does it rain in Monterrey?
On long-term average, Monterrey has about 61 days a year with at least 2 mm of rain or snow. The annual total is roughly 610 mm.

Weather in nearby cities