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Aomori weather by month: averages, rainfall & climate trends

Aomori swings through a wide annual range, with 26.0°C between the monthly means of its warmest and coldest months. The heavier rain months run from July to September. Aomori weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+2.0°Chigh above average

19° / 14°Today
17° / 9°Average
see today in detail →

How it's changed

+2.9°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4979frost days a year now (2016–2025) · 123 in the 1940sfrost days a year · 123 in the 1940s27days above 30°C a year now (2016–2025) · 8 in the 1940sdays above 30°C · 8 in the 1940s+2.9°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 87 mmhigh 1°low −5°February, rain 77 mmhigh 2°low −4°March, rain 94 mmhigh 6°low −1°April, rain 92 mmhigh 13°low 5°May, rain 95 mmhigh 19°low 11°June, rain 109 mmhigh 23°low 15°July, rain 156 mmhigh 26°low 20°August, rain 168 mmhigh 28°low 21°September, rain 153 mmhigh 24°low 16°October, rain 107 mmhigh 17°low 10°November, rain 92 mmhigh 10°low 4°December, rain 96 mmhigh 4°low −2°wettest month August, 168 mm · 1,326 mm a yearsee month by month →

Right now

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

Right now

13.7°

14°feels like
93%humidity
13°dew point
4 km/hfrom E
UV index0.0
sunrise05:53sunset16:50day length10h 57m
TodayPartly cloudy19°14°
WedLight rain18°13°
ThuPartly cloudy13°10°
FriPartly cloudy14°9°
SatOvercast15°9°
SunOvercast18°14°
MonLight rain13°11°

On this date: October 20

Today (forecast)
19° / 14°
Average for October 20
17° / 9°

High above average · +2.0°C

  • Highest since 1940: 22.2° · 1976
  • Lowest since 1940: 2.6° · 1963
  • One year ago: 11° / 6°

Every October 20 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 20 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 Aomori is sampled from the ECMWF ERA5 reanalysis at 40.82°N, 140.73°E, with daily records since 1940.

Coordinates
40.82°N, 140.73°E
Time zone
Asia/Tokyo
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: +1.8°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 27.9°C and nights around 21.3°C. In a typical recent year, around 25 days reach 30°C or more. The coolest month is January, when afternoons reach about 1.0°C and overnight lows sit around −4.5°C.

In total, Aomori averages about 1,326 mm of precipitation a year; August is usually the wettest month (168 mm) and February the driest (77 mm). Precipitation falls on roughly 142 days in a typical year.

Over the full record (since 1940), the annual mean temperature in Aomori has risen by 2.9°C between its first decade and its last. Frost days have thinned out, from around 125 a year in the first decade to about 80 now.

Climate graph (climograph)

August is the warmest month, January the coolest: a yearly swing of 26°C. Wettest month: August (~168 mm). Whole year averages ~1,326 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 142 rainy days a year: most in December (~14), fewest in May (~10).

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.

Aomori 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
January1.0°−4.5°87 mm139.4 h12.6° (1988)−16.9° (2000)
February1.7°−4.2°77 mm1110.4 h16.8° (2024)−15.2° (1986)
March5.7°−0.9°94 mm1211.7 h22.2° (2023)−12.6° (1941)
April13.5°5.3°92 mm1113.1 h26.7° (2002)−6.3° (1966)
May19.3°11.0°95 mm1014.3 h32.6° (2019)−0.2° (1971)
June22.8°15.5°109 mm1014.9 h33.3° (2014)4.7° (1954)
July26.3°20.0°156 mm1314.7 h35.3° (2004)9.7° (1966)
August27.9°21.3°168 mm1313.6 h38.0° (2023)12.7° (1976)
September23.7°16.4°153 mm1212.3 h35.0° (2020)5.9° (1960)
October17.4°9.7°107 mm1110.9 h28.5° (1945)−1.0° (1950)
November10.1°3.7°92 mm129.7 h23.1° (2023)−10.8° (1998)
December3.6°−2.0°96 mm149.1 h16.9° (1990)−13.0° (1966)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +2.9°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: +0.29°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

Dec–Feb is warming fastest: +0.34°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: 8.1 early in the record → 26.7 recently. Frost days: 123 → 79.

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 2000: 38.0°C / −16.9°C.

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

Annual rainfall

~1,326 mm/year on average. Last decade: +9% vs that average. Long-term trend: +21 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 Aomori

Which is the warmest month in Aomori?
On long-term average, the warmest month in Aomori is August (mean daily temperature of about 24.2°C) and the coolest is January (about −1.8°C).
How does today's temperature in Aomori compare to the historical average?
On October 20, 2026, Aomori is forecast to reach a high of 18.5°C and a low of 13.9°C. The long-term average for this date (the full record since 1940) is a high of 16.5°C and a low of 8.7°C, so today's high is 2.0°C warmer than that average.
How much has Aomori warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Aomori is about 2.9°C warmer.
How much does it rain in Aomori?
Aomori receives about 1,326 mm of precipitation per year on long-term average, with August typically the wettest month.
What is the average temperature in Aomori?
Over the full record (since 1940), the annual mean temperature in Aomori is about 10.8°C. The warmest month is August and the coolest is January.
What are the average temperatures in Aomori by month?
Average daily highs and lows for each month in Aomori (°C, full record since 1940): January 1°/−5°, February 2°/−4°, March 6°/−1°, April 13°/5°, May 19°/11°, June 23°/15°, July 26°/20°, August 28°/21°, September 24°/16°, October 17°/10°, November 10°/4°, December 4°/−2°.
What is the weather like in Aomori in summer?
June to August is summer in Aomori, and it is wet and pleasantly warm. It warms from 23°C by day and 15°C at night in June to 28°C and 21°C in August. Rain picks up through the season: 10 rainy days and 109 mm in June, 13 days and 168 mm in August. No season is wetter.
What is the weather like in Aomori in winter?
December to February is winter in Aomori, and it is cold. Afternoons run 1–4°C and nights −5 to −2°C; January is the coldest month. Rain and snow are steady at around 87 mm a month, spread over roughly 13 days.
What is the weather like in Aomori in spring?
In spring, March through May, Aomori is cool. It warms from 6°C by day and −1°C at night in March to 19°C and 11°C in May. Rain falls on about 11 days a month, adding up to around 93 mm.
What is the weather like in Aomori in autumn?
In autumn, September through November, Aomori is wet and fairly mild. September still brings 24°C afternoons and 16°C nights, November only 10°C and 4°C. Rain eases through the season, 153 mm in September to 92 mm in November.
How many days a year does it rain in Aomori?
On long-term average, Aomori has about 142 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,326 mm.

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