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Mahajanga weather by month: averages, rainfall & climate trends

Warmth in Mahajanga is remarkably steady: only 2.9°C separates the warmest month from the coolest, so there is no cold season to speak of. Rainfall is strongly seasonal: the bulk of the year's rain falls between December and March. Mahajanga weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.8°Chigh above average

34° / 25°Today
31° / 24°Average
see today in detail →

How it's changed

+1.1°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49254days above 30°C a year now (2016–2025) · 124 in the 1940sdays above 30°C · 124 in the 1940s+1.1°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 388 mmhigh 29°low 25°February, rain 310 mmhigh 29°low 25°March, rain 210 mmhigh 30°low 25°April, rain 63 mmhigh 31°low 25°May, rain 9 mmhigh 31°low 24°June, rain 1 mmhigh 29°low 22°July, rain 2 mmhigh 29°low 21°August, rain 2 mmhigh 29°low 21°September, rain 4 mmhigh 30°low 22°October, rain 20 mmhigh 31°low 24°November, rain 84 mmhigh 31°low 25°December, rain 221 mmhigh 30°low 25°wettest month January, 388 mm · 1,314 mm a yearsee month by month →

Right now

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

Right now

26.7°

31°feels like
84%humidity
24°dew point
13 km/hfrom W
UV index0.0
sunrise05:23sunset17:55day length12h 32m
TodayPartly cloudy34°25°
ThuMostly clear35°25°
FriMostly clear36°26°
SatPartly cloudy35°26°
SunPartly cloudy35°25°
MonPartly cloudy35°24°
TueMostly clear35°24°

On this date: October 21

Today (forecast)
34° / 25°
Average for October 21
31° / 24°

High above average · +2.8°C

  • Highest since 1940: 34.4° · 2020
  • Lowest since 1940: 22.5° · 1987
  • One year ago: 31° / 25°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 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 Mahajanga is sampled from the ECMWF ERA5 reanalysis at 15.72°S, 46.32°E, with daily records since 1940.

Coordinates
15.72°S, 46.32°E
Time zone
Indian/Antananarivo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

30 of the last 31 days were warmer than the historical average for that date. Average difference: +1.1°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

The year peaks in April, at around 31.0°C by mid-afternoon, with nights around 25.0°C. The coolest month is July, when afternoons reach about 28.9°C and overnight lows sit around 21.1°C.

Mahajanga picks up roughly 1,314 mm a year, with a peak of 388 mm in January and as little as 1 mm in June.

Over the full record (since 1940), the annual mean temperature in Mahajanga has risen by 1.1°C between its first decade and its last. Days above 30°C have grown noticeably more frequent, from around 125 a year in the first decade to about 255 in the last.

Climate graph (climograph)

April is the warmest month, July the coolest: a yearly swing of 3°C. Wettest month: January (~388 mm). Whole year averages ~1,314 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: the record's own proxy for how sunny the month is.

Mahajanga 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 lowRainDaylightHighestLowest
January29.3°25.0°388 mm12.8 h34.0° (2025)22.8° (1965)
February29.3°25.0°310 mm12.5 h33.1° (1966)22.9° (1945)
March30.2°25.1°210 mm12.1 h34.1° (2024)22.0° (1965)
April31.0°25.0°63 mm11.6 h34.9° (2024)20.4° (1978)
May30.6°23.6°9 mm11.3 h34.4° (2024)19.5° (1950)
June29.4°21.9°1 mm11.1 h32.2° (2025)18.1° (1986)
July28.9°21.1°2 mm11.2 h32.1° (1982)18.0° (1996)
August29.4°21.4°2 mm11.5 h32.3° (2024)18.1° (2003)
September30.2°22.4°4 mm11.9 h33.4° (2018)18.6° (1993)
October30.9°24.0°20 mm12.4 h35.0° (2024)20.3° (1966)
November30.6°24.9°84 mm12.7 h35.1° (2023)22.1° (1994)
December29.9°25.1°221 mm12.9 h34.7° (2024)22.9° (1973)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.1°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: +0.14°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: +0.19°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: 123.6 early in the record → 253.9 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

Hottest day since 1940 in 2023, coldest in 1996: 35.1°C / 18.0°C.

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

Annual rainfall

~1,314 mm/year on average. Last decade: +6% vs that average. Long-term trend: +18 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 Mahajanga

Which is the warmest month in Mahajanga?
On long-term average, the warmest month in Mahajanga is April (mean daily temperature of about 27.7°C) and the coolest is July (about 24.8°C).
How does today's temperature in Mahajanga compare to the historical average?
On October 21, 2026, Mahajanga is forecast to reach a high of 33.8°C and a low of 24.9°C. The long-term average for this date (the full record since 1940) is a high of 31.0°C and a low of 24.4°C, so today's high is 2.8°C warmer than that average.
How much has Mahajanga warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Mahajanga is about 1.1°C warmer.
How much does it rain in Mahajanga?
Mahajanga receives about 1,314 mm of precipitation per year on long-term average, with January typically the wettest month.
What is the average temperature in Mahajanga?
Over the full record (since 1940), the annual mean temperature in Mahajanga is about 26.6°C. The warmest month is April and the coolest is July.
What are the average temperatures in Mahajanga by month?
Average daily highs and lows for each month in Mahajanga (°C, full record since 1940): January 29°/25°, February 29°/25°, March 30°/25°, April 31°/25°, May 31°/24°, June 29°/22°, July 29°/21°, August 29°/21°, September 30°/22°, October 31°/24°, November 31°/25°, December 30°/25°.

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