WeatherJourney.com

Mazatlán weather by month — averages, rainfall & climate trends

Average temperatures and rainfall by month, a climate graph, today's conditions versus the long-term average, and how the climate has shifted since 1940 — all on one page for Mazatlán, Mexico.

Right now

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

Right now

25.0°

31°feels like
96%humidity
24°dew point
4 km/hfrom N
sunrise05:31sunset18:52day length13h 21m
TodayMostly clear36°25°
WedOvercast36°26°
ThuPartly cloudy34°27°
FriOvercast33°27°
SatPartly cloudy33°26°
SunOvercast34°26°
MonOvercast33°25°

On this date — July 21

Today (forecast)
36° / 25°
Average for July 21
30° / 27°

Warmer than usual · 6.5°C above the average high

  • Record high: 31.4° · 2023
  • Record low: 23.9° · 1985
  • One year ago: 30.6°

Every July 21 in history — coldest to hottest

Daily highsDaily lows

Dots show daily highs (top) and lows (bottom) for each July 21 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 Mazatlán is sampled from the ECMWF ERA5 reanalysis at 23.22°N, 106.42°W, with daily records since 1940.

Coordinates
23.22°N, 106.42°W
Time zone
America/Mazatlan
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

31 of the last 31 days were warmer than the historical average for that date. Average difference: +1.9°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 — 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 — what a typical year looks like, from the full record.

Climate overview

Mazatlán is warm in every month of the year — the seasonal dip amounts to just 7.3°C. The warmest month is August, with a daily mean around 28.0°C and typical afternoon highs of 29.5°C. At the other extreme, February averages 20.7°C, with typical overnight lows of 18.8°C.

Rainfall is strongly seasonal: the bulk of the year's rain falls between July and October. In total, Mazatlán averages about 678 mm of precipitation a year; September is usually the wettest month (190 mm) and May the driest (1 mm).

Comparing the record's first decade with its most recent one, Mazatlán now averages 1.0°C warmer than it did in the 1940s. Days above 30°C have grown noticeably more frequent — from around 2 a year in the first decade to about 70 in the last.

Climate graph (climograph)

August is the warmest month, February the coolest — a yearly swing of 7°C. Wettest month: September (~190 mm). Whole year averages ~678 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).

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre — a measured proxy for how sunny the month is.

Mazatlán 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. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainDaylightRecord highRecord low
January22.9°18.9°21 mm10.7 h28.0° (2024)13.6° (1955)
February22.8°18.8°11 mm11.2 h27.0° (2005)11.2° (2011)
March23.0°19.1°6 mm11.8 h26.7° (1942)14.2° (2001)
April24.2°20.5°1 mm12.5 h29.8° (1990)16.5° (1944)
May26.1°22.7°1 mm13.1 h30.9° (2025)18.8° (2010)
June28.0°25.4°19 mm13.4 h31.5° (2006)20.7° (1943)
July29.4°26.6°128 mm13.3 h32.7° (2006)23.4° (1974)
August29.5°26.5°187 mm12.8 h32.1° (2001)23.8° (1975)
September29.2°26.4°190 mm12.1 h32.1° (2023)22.9° (1963)
October28.6°25.5°70 mm11.4 h32.3° (2025)21.3° (1980)
November26.5°22.7°22 mm10.9 h30.9° (1965)17.5° (1979)
December24.2°20.2°23 mm10.6 h28.8° (2006)13.8° (2020)

How it has changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.0°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: +0.12°C per decade.

One point per year — 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

Jun–Aug is warming fastest: +0.15°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: 2.3 early in the record → 70.0 recently. Frost days: 0 → 0.

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

All-time high in 2006, all-time low in 2011: 32.7°C / 11.2°C.

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

Annual rainfall

~678 mm/year on average. Last decade ran −7% vs that average. Long-term trend: +17 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 — ~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).

Mazatlán — Frequently asked questions

Which is the warmest month in Mazatlán?
On long-term average, the warmest month in Mazatlán is August (mean about 28.0°C) and the coolest is February (about 20.7°C).
How does today's temperature in Mazatlán compare to the historical average?
On 2026-07-21, Mazatlán is forecast to reach a high of 36.0°C and a low of 25.0°C. The long-term average for this date (the full record since 1940) is a high of 29.5°C and a low of 26.7°C — today's high is 6.5°C warmer than that average.
How much has Mazatlán warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Mazatlán is about 1.0°C warmer.
How much does it rain in Mazatlán?
Mazatlán receives about 678 mm of precipitation per year on long-term average, with September typically the wettest month.
What is the average temperature in Mazatlán?
Over the full record (since 1940), the annual mean temperature in Mazatlán is about 24.5°C. The warmest month is August and the coolest is February.
What are the average temperatures in Mazatlán by month?
Average daily highs and lows for each month in Mazatlán (°C, full record since 1940): January 23°/19°, February 23°/19°, March 23°/19°, April 24°/20°, May 26°/23°, June 28°/25°, July 29°/27°, August 29°/27°, September 29°/26°, October 29°/26°, November 26°/23°, December 24°/20°.
How many days a year does it rain in Mazatlán?
On long-term average, Mazatlán has about 73 days a year with measurable rain, totalling roughly 678 mm.

Weather in nearby cities