Temperature records for Ibaraki
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Ibaraki, ―
Stations in Ibaraki
All-time records in Ibaraki
Records among the stations on this page (statistics as of November 1, 2026).
| Record | Station | Value | Date |
|---|---|---|---|
| Highest temperature | Koga | 40.6°C | Aug 5, 2025 |
| Lowest temperature | Tsukuba | -17.0°C | Feb 5, 1952 |
| Heaviest daily rainfall | Kashima | 304.0 mm | Oct 27, 1999 |
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 Ibaraki
Summer heat in Ibaraki Prefecture grows stronger the farther west you go. The record high is 40.6°C at Koga, at the western edge of the prefecture, observed on August 5, 2025. Lining up the August maximum on the 30-year average for 1996–2025 gives 32.2°C at Koga, 31°C at Tsukuba, and 30.4°C at Mito near the sea, so whether the sea breeze reaches a place directly sets the order. Inland Koga lies where air carrying heat loses the coolness of the sea as it crosses the plain.
For the cold extremes, the prefecture's records converge on a single day, February 5, 1952. Tsukuba observed -17°C on this day, the prefecture's record low, and Mito's record low of -12.7°C is from the same day. The normal January minimum is -2.7°C at Tsukuba and -1.2°C at Koga, but the average maximum is in the 9°C range at every station, mild enough that a jacket will do in the daytime. On the plain, where heat escapes from the ground on clear, calm nights, the temperature swings widely within a single day.
While temperatures split east and west, the skies match well across the prefecture. The annual share of days with less than 1 mm of precipitation is nearly identical, at 72.3% at Mito, 72.8% at Tsukuba, and 72.9% at Koga, and in January all 3 stations rise together to 86.9%, 87.3%, and 88.4%. The lowest month is June at every station. Substantial rain comes in that season, and the daily rainfall record is 276.6 mm, set at Mito on June 29, 1938, the highest value 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 Ibaraki (Mito)
The normals for Mito represent the stations in Ibaraki. 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 | 3.3 | 9.2 | -1.8 | 54.5 |
| Feb | 4.1 | 9.8 | -1.2 | 53.8 |
| Mar | 7.4 | 13.0 | 2.1 | 102.8 |
| Apr | 12.3 | 17.8 | 7.0 | 116.7 |
| May | 17.0 | 22.0 | 12.5 | 144.5 |
| Jun | 20.3 | 24.5 | 17.0 | 135.7 |
| Jul | 24.2 | 28.5 | 21.0 | 141.8 |
| Aug | 25.6 | 30.0 | 22.2 | 116.9 |
| Sep | 22.1 | 26.4 | 18.6 | 186.3 |
| Oct | 16.6 | 21.2 | 12.5 | 185.4 |
| Nov | 10.8 | 16.3 | 5.9 | 79.7 |
| Dec | 5.6 | 11.4 | 0.5 | 49.6 |
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 Mito 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.