Temperature records for Iwate
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Iwate, ―
Stations in Iwate
All-time records in Iwate
Records among the stations on this page (statistics as of November 1, 2026).
| Record | Station | Value | Date |
|---|---|---|---|
| Highest temperature | Iwaizumi | 38.5°C | Aug 12, 1994 |
| Lowest temperature | Yabukawa | -27.6°C | Feb 17, 1988 |
| Heaviest daily rainfall | Omoto | 484.0 mm | Aug 13, 2023 |
Range of records by station
Each bar is one station: the left dot is its record low and the right dot its record high. The statistical period differs by station, depending on when observations began or the station moved. The dates are on each station's page.
The climate of Iwate
The story of Iwate Prefecture's records opens in a slightly unexpected place. The record high among the stations covered here is not at inland Morioka but at Miyako on the Pacific coast, 37.3°C, observed on July 23, 1933. The lowest is -20.6°C, recorded on January 26, 1945, at Morioka in the Kitakami Basin. Everyday temperatures and record extremes do not always rank the same way: comparing the August maximum on the 30-year average for 1996–2025, Morioka is 28.9°C and Miyako 26.7°C, a neat reversal of the order.
The contrast between the interior and the Sanriku coast shows most plainly in winter. The average January minimum is -5.2°C in Morioka and -2.4°C in Ofunato, on the coast in the southern part of the prefecture, a gap of 2.8°C. In the daytime, too, Miyako's January maximum is 5.2°C, more than 3°C above Morioka's 2°C. In a basin wedged between the Ou Mountains and the Kitakami Highlands, where the wind has trouble getting through, and on a coastline next to a sea whose water is slow to cool, the same January passes as if it were a different season.
Precipitation changes its main season. The annual share of days with less than 1 mm of precipitation is 74.6% in Miyako and 65.4% in Morioka, and in Miyako it rises to 85.6% in January, so the coast is often sunny in winter. In July, however, it drops to 62.3%, and the daily rainfall record of 319 mm also dates from July 8, 2000. Only in the season when moist air flows in from the south does the dry seaside become the place that takes the heaviest rain among the stations covered here.
Record values in this description are based on data collected as of September 2026, and the normal statistics on the 30 years 1996–2025.
Monthly normals for Iwate (Morioka)
The normals for Morioka represent the stations in Iwate. Normals for the other stations are on each station's page.
Temperature (monthly normals)
The lines show monthly normals: the upper line is the monthly mean of the daily high and the lower line the monthly mean of the daily low, and the middle line is the monthly mean temperature. Touch the point for a month to read its values. Normals are the 1991–2020 average.
Precipitation (monthly normals, mm)
Table of monthly normals
| Month | Mean | High | Low | Precipitation |
|---|---|---|---|---|
| Jan | -1.6 | 2.0 | -5.2 | 49.4 |
| Feb | -0.9 | 3.2 | -4.8 | 48.0 |
| Mar | 2.6 | 7.5 | -1.8 | 82.1 |
| Apr | 8.7 | 14.4 | 3.2 | 85.4 |
| May | 14.5 | 20.3 | 9.1 | 106.5 |
| Jun | 18.8 | 24.1 | 14.2 | 109.4 |
| Jul | 22.4 | 27.1 | 18.8 | 197.5 |
| Aug | 23.5 | 28.4 | 19.8 | 185.4 |
| Sep | 19.3 | 24.3 | 15.2 | 151.7 |
| Oct | 12.6 | 17.9 | 7.9 | 108.7 |
| Nov | 6.2 | 10.9 | 1.8 | 85.6 |
| Dec | 0.8 | 4.5 | -2.5 | 70.2 |
Temperatures are in degrees Celsius (°C) and precipitation in mm. Blank cells have no normal.
Annual mean temperature (1996–2025)
The yearly average of the daily mean temperature (the line is broken in years with many missing values). Observing conditions at Morioka changed on December 4, 2007; June 25, 2008 (for example, a relocation or new instruments), so the statistics may not be continuous across those dates.
The normals listed here are averages over the 30 years from 1991 to 2020. They are fixed values that stay the same until the next revision of the normals, and they show how warm or cold that month usually is in that area.