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Imabari weather by month: averages, rainfall & climate trends

Imabari swings through a wide annual range, with 21.4°C between the monthly means of its warmest and coldest months. The heavier rain months run from May to September. Imabari weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+1.2°Chigh near average

21° / 19°Today
20° / 15°Average
see today in detail →

How it's changed

+1.8°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–492frost days a year now (2016–2025) · 10 in the 1940sfrost days a year · 10 in the 1940s50days above 30°C a year now (2016–2025) · 12 in the 1940sdays above 30°C · 12 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 76 mmhigh 9°low 4°February, rain 86 mmhigh 9°low 5°March, rain 113 mmhigh 13°low 8°April, rain 139 mmhigh 18°low 13°May, rain 160 mmhigh 22°low 17°June, rain 253 mmhigh 25°low 21°July, rain 218 mmhigh 29°low 25°August, rain 160 mmhigh 30°low 26°September, rain 209 mmhigh 27°low 23°October, rain 131 mmhigh 22°low 17°November, rain 90 mmhigh 17°low 12°December, rain 73 mmhigh 12°low 7°wettest month June, 253 mm · 1,709 mm a yearsee month by month →

Right now

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

Right now

20.2°

22°feels like
94%humidity
19°dew point
10 km/hfrom NE
UV index0.0
sunrise06:22sunset17:21day length10h 60m
TodayRain21°19°
TuePartly cloudy22°15°
WedMostly clear17°13°
ThuOvercast17°11°
FriShowers18°15°
SatMostly clear19°11°
SunOvercast19°9°

On this date: October 26

Today (forecast)
21° / 19°
Average for October 26
20° / 15°

High near average · +1.2°C

  • Highest since 1940: 24.9° · 2016
  • Lowest since 1940: 9.9° · 1958
  • One year ago: 22° / 16°

Every October 26 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 26 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 Imabari is sampled from the ECMWF ERA5 reanalysis at 34.07°N, 133.00°E, with daily records since 1940.

Coordinates
34.07°N, 133.00°E
Time zone
Asia/Tokyo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

23 of the last 31 days were warmer than the historical average for that date. Average difference: +1.4°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

August brings the year's peak warmth, with afternoons typically reaching 30.3°C and nights around 25.8°C. On about 125 nights a year, the temperature never drops below 20°C. At the other extreme, January brings afternoon highs of about 8.8°C and typical overnight lows of 4.4°C.

The yearly total for Imabari comes to about 1,709 mm; monthly amounts range from 73 mm in December up to 253 mm in June. A typical year brings rain or snow on around 127 days.

Comparing the record's first decade with its most recent one, Imabari now averages 1.8°C warmer than it did in the 1940s. Days above 30°C have grown noticeably more frequent, from around 12 a year in the first decade to about 50 in the last.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 21°C. Wettest month: June (~253 mm). Whole year averages ~1,709 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 127 rainy days a year: most in July (~14), fewest in November (~8).

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.

Imabari 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
January8.8°4.4°76 mm1010.0 h19.3° (1997)−3.8° (1942)
February9.4°4.6°86 mm910.8 h21.0° (1954)−4.6° (1981)
March12.9°7.5°113 mm1111.7 h23.3° (1979)−2.7° (1977)
April18.1°12.5°139 mm1012.9 h26.2° (1973)3.4° (1972)
May22.0°16.8°160 mm1013.8 h27.7° (1991)9.6° (2013)
June25.3°20.9°253 mm1314.3 h31.4° (2022)13.9° (1981)
July29.1°25.0°218 mm1414.1 h34.2° (1994)18.7° (1945)
August30.3°25.8°160 mm1213.3 h33.6° (1998)20.5° (1956)
September27.2°22.7°209 mm1312.2 h33.5° (2024)14.1° (1987)
October22.0°17.1°131 mm811.1 h30.1° (2018)8.1° (1986)
November16.8°12.0°90 mm810.2 h26.0° (2023)3.2° (1966)
December11.5°7.1°73 mm99.7 h22.1° (2018)−1.2° (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 +1.8°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: +0.20°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

Sep–Nov is warming fastest: +0.24°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: 12.1 early in the record → 50.4 recently. Frost days: 10 → 2.

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 1994, coldest in 1981: 34.2°C / −4.6°C.

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

Annual rainfall

~1,709 mm/year on average. Last decade: +5% vs that average. Long-term trend: +32 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 Imabari

Which is the warmest month in Imabari?
On long-term average, the warmest month in Imabari is August (mean daily temperature of about 27.9°C) and the coolest is January (about 6.5°C).
How does today's temperature in Imabari compare to the historical average?
On October 26, 2026, Imabari is forecast to reach a high of 21.3°C and a low of 19.0°C. The long-term average for this date (the full record since 1940) is a high of 20.1°C and a low of 15.3°C, so today's high is 1.2°C warmer than that average.
How much has Imabari warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Imabari is about 1.8°C warmer.
How much does it rain in Imabari?
Imabari receives about 1,709 mm of precipitation per year on long-term average, with June typically the wettest month.
What is the average temperature in Imabari?
Over the full record (since 1940), the annual mean temperature in Imabari is about 17.0°C. The warmest month is August and the coolest is January.
What are the average temperatures in Imabari by month?
Average daily highs and lows for each month in Imabari (°C, full record since 1940): January 9°/4°, February 9°/5°, March 13°/8°, April 18°/13°, May 22°/17°, June 25°/21°, July 29°/25°, August 30°/26°, September 27°/23°, October 22°/17°, November 17°/12°, December 12°/7°.
What is the weather like in Imabari in summer?
June to August is summer in Imabari, and it is wet and warm. June starts at 25°C by day and 21°C at night; by August it is 30°C and 26°C. Rain eases through the season: 13 rainy days and 253 mm in June, 12 days and 160 mm in August. No season is wetter.
What is the weather like in Imabari in winter?
December to February is winter in Imabari, and it is on the cool side. Daytime highs sit at 9–12°C and nights at 4–7°C; January is the coldest month. Rain falls on about 9 days a month, adding up to around 78 mm. It is the driest season of the year.
What is the weather like in Imabari in spring?
March to May is spring in Imabari, and it is wet and fairly mild. It warms from 13°C by day and 8°C at night in March to 22°C and 17°C in May. Rain is steady at around 138 mm a month, spread over roughly 10 days.
What is the weather like in Imabari in autumn?
In autumn, September through November, Imabari is wet and pleasantly warm. September still brings 27°C afternoons and 23°C nights, November only 17°C and 12°C. Rain falls off from 209 mm on 13 days in September to 90 mm on 8 days in November.
How many days a year does it rain in Imabari?
On long-term average, Imabari has about 127 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,709 mm.

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