WEATHERblaze

Iwate Historical Weather Data & Climate

Historical Climate Data for 30 Cities
1981–2025
Japan

Quick Climate Facts

(19812025)
Hottest City
🔥
Fujisawachō-niinuma
Jul High 31.0°C
Coldest City
❄️
Ichinohe
Jan Low -13.0°C
Wettest City
🌧
Shizukuishi
1365 mm/yr
Driest City
🏜️
Iwaizumi
1200 mm/yr
Hottest Month
🌡
August
Avg 22.7°C
Max 30.7°C
Coldest Month
🧊
February
Avg -2.1°C
Min -10.4°C
Cities With Data
🏙️
30
cities in Iwate
Data Coverage
📅
45 yrs
19812025

Iwate Climate Overview

Iwate has a temperate climate with warm summers and freezing winters.

Iwate has an average annual temperature of 10.0°C across all 30 cities, with approximately 1334 mm of annual precipitation and average humidity of 85%. Temperatures peak in August and drop to their lowest in February, while rainfall is highest during summer months.

The warmest city is Fujisawachō-niinuma with average July highs of 31.0°C, while Ichinohe is the coldest with average January lows of -13.0°C. Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions. These seasonal patterns make summer ideal for outdoor activities, while winters bring freezing conditions and heavy snowfall.

🏙️ Cities in Iwate — Weather History

📊 Iwate Monthly Climate Data

Monthly Climate Data
Month🌤️HighLowAvgHumid %Rain (mm)Wind (m/s)Solar (kWh/m²)
January❄️4.9°C-9.8°C-2.4°C89%682.91.90
February❄️6.3°C-10.4°C-2.1°C88%583.02.70
March12.3°C-7.4°C2.5°C84%842.73.70
April19.0°C-2.7°C8.1°C81%992.14.60
May23.4°C2.4°C12.9°C81%1091.64.90
June26.0°C8.0°C17.0°C84%1191.34.90
July🌧️29.5°C12.9°C21.2°C86%1611.34.50
August🌧️30.7°C14.7°C22.7°C86%1671.34.40
September🌧️27.5°C9.3°C18.4°C85%1661.63.60
October21.9°C2.5°C12.2°C84%1251.82.90
November16.5°C-2.7°C6.9°C85%952.12.10
December10.6°C-7.0°C1.8°C88%822.51.60

Showing average climate conditions across 45 years (1981–2025) · averaged across all 30 cities in Iwate

🌦 Weather in Iwate Across Seasons

❄️ Winter in Iwate

February is Iwate's coldest month, with average lows reaching -10.4°C.
🌡️December to February (avg) · -9.1°C7.3°C

🧥 Pack heavy layers and prepare for snow — this is a Severe Winter destination.

☀️ Summer in Iwate

Summer temperatures in Iwate peak in August, climbing to 30.7°C.
🌡️July to September (avg) · 12.3°C29.2°C

🌤️ Early mornings and evenings are most comfortable during this Hot Summer season.

🌧️ Rainy Season in Iwate

Iwate sees its highest rainfall in August, receiving approximately 167 mm of precipitation.
🌧️July to September (avg) ·  up to 167 mm

☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.

📈 Iwate Monthly Averages

🌡️ Temperature Patterns

Region-wide monthly averages across 30 cities · 19812025 · °C

🌡️ Iwate Monthly Temperature Guide

August is the hottest month in Iwate, with average highs reaching 30.7°C, while February is the coldest with lows dropping to -10.4°C.

Temperatures rise steadily from spring, peak in August, and gradually decline through autumn into winter.

These seasonal patterns make summer ideal for outdoor activities, while winters bring freezing conditions and heavy snowfall.

🌧️ Rainfall Distribution

Region-wide monthly rainfall · 19812025 · mm/month

💨 Humidity & Wind Speed

Monthly averages · 19812025

🌧 Rainfall & Humidity in Iwate

Iwate receives its highest rainfall in August, while humidity peaks during winter months.
🌧️ Wettest: August167 mm☀️ Driest: February58 mm

💧 Humidity peaks at 89% in January · annual avg 85%

📅 Iwate Yearly Climate Trends

The warmest year on record was 2024 (avg: 11.7°C), while the coldest year was 1984 (avg: 8.3°C).

📊 Key Climate Trends

  • 🌡️ Iwate's temperature shows a slight warming trend over the past decade
  • 📈 Minimum temperatures show a slight warming trend in recent years
  • 🌧️ Rainfall has increased noticeably in recent years compared to earlier periods

🌡️ Annual Temperature Trend

View Range:

Averaged across all 30 cities in Iwate · Last 10 years · °C

Iwate's temperature shows a slight warming trend over the past decade. The region-wide average sits at 10.0°C with annual rainfall averaging 1334 mm.

🌧️ Annual Precipitation

View Range:

Averaged across all 30 cities in Iwate · Last 10 years · mm/year

Annual rainfall in Iwate shows noticeable variation. Rainfall has increased noticeably in recent years compared to earlier periods.
📅 Yearly Climate Data Overview

🔥 hottest  ·  ❄️ coldest  ·  🌧️ wettest

ℹ️ Values are averages across all 30 cities in Iwate for each year.

YearMin TempAvg TempMax TempRainfall (mm)Avg HumidityAvg Wind
2025 🌧️
2.1°C11.2°C20.3°C171886%2.0 m/s
2024 🔥
2.3°C11.7°C21.0°C168086%2.0 m/s
2023
2.0°C11.5°C20.9°C158386%1.9 m/s
2022
1.2°C10.0°C18.9°C148486%1.9 m/s
2021
1.4°C10.6°C19.9°C146086%2.1 m/s
2020
2.2°C10.7°C19.1°C158986%2.0 m/s
2019
1.3°C10.9°C20.4°C126784%2.0 m/s
2018
0.7°C10.4°C20.1°C146886%2.0 m/s
2017
0.9°C9.6°C18.4°C140086%2.0 m/s
2016
0.8°C10.3°C19.7°C139785%2.0 m/s

Showing 1 to 10 of 45 years

🏙️ Explore More Cities in Iwate

❓ Frequently Asked Questions

What is the hottest city in Iwate?
Fujisawachō-niinuma is the hottest city in Iwate with an average July high of 31.0°C based on 45 years of data. View Fujisawachō-niinuma weather history →
What is the coldest city in Iwate?
Ichinohe is the coldest city with average January lows of -13.0°C. View Ichinohe weather history →
Which city in Iwate gets the most rain?
Shizukuishi is the wettest city in Iwate with approximately 1365 mm of annual precipitation on average.
What is the warmest month in Iwate?
August is the warmest month in Iwate, with region-wide average highs of 30.7°C and average lows of 14.7°C.
What is the coldest month in Iwate?
February is the coldest month in Iwate with average lows of -10.4°C and average highs of 6.3°C.
What is the rainiest month in Iwate?
August is the rainiest month in Iwate with approximately 167 mm on average, while February is the driest with 58 mm.
How many cities in Iwate have weather data?
WeatherBlaze has historical weather data for 30 cities in Iwate, covering 45 years of climate records from 1981 to 2025.
Where does this climate data come from?
All data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis data. It includes monthly temperature, precipitation, humidity, wind speed, and solar radiation.

📡 Data Source

All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.

Parameters included:
  • Temperature (Min, Max)
  • Precipitation
  • Relative Humidity
  • Wind Speed
  • Solar Radiation
Data specifications:
  • Resolution: Monthly
  • Spatial: 0.5° × 0.625°
  • Source: MERRA-2
  • Coverage: 19812025
  • Cities: 30 in Iwate