Temperature records for Chiba
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Chiba, ―
Stations in Chiba
All-time records in Chiba
Records among the stations on this page (statistics as of November 1, 2026).
| Record | Station | Value | Date |
|---|---|---|---|
| Highest temperature | Ushiku | 40.2°C | Jul 20, 2004 |
| Lowest temperature | Sakura | -12.7°C | Jan 20, 1984 |
| Heaviest daily rainfall | Mobara | 391.0 mm | Sep 8, 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 Chiba
In Chiba Prefecture, surrounded by the sea on three sides, both heat and cold have their edges rounded off. Among the stations covered here, the record high is 38.5°C in the city of Chiba on August 7, 2015, and the record low is -7.3°C at Choshi, set on February 13, 1893. On the 30-year average for 1996–2025, too, the January minimum is 3°C at Choshi and Katsuura and 1.2°C at Tateyama, so no station's average falls below 0°C. The sea, carrying the warmth of the Kuroshio Current, keeps winters relatively mild.
Summer differs between the inner and outer sides of the Boso Peninsula. The average August maximum is 31.4°C in the city of Chiba, against only 29°C at Choshi and 29.3°C at Katsuura, which face the open ocean. What is more, at Choshi and Katsuura the share of days with less than 1 mm of precipitation peaks for the year in that same August, at 78.1% and 79.2%. This is a summer found only by the sea, with many sunny days yet temperatures that never fully climb.
At those 2 stations, rain gathers in autumn, and the month with the lowest the share of days with less than 1 mm of precipitation is October, at 60.5% and 61.1%. On September 22, 1996, 326 mm fell at Katsuura and 314 mm at Tateyama, so the daily rainfall records of these 2 stations fall on the same day. Choshi's daily rainfall record is 311.6 mm on August 28, 1947, and the city of Chiba's is 351 mm on August 13, 2026, both from the season when moist air arrives from the sea.
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 Chiba (Choshi)
The normals for Choshi represent the stations in Chiba. 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 | 6.6 | 10.1 | 2.9 | 105.5 |
| Feb | 6.9 | 10.3 | 3.3 | 90.5 |
| Mar | 9.7 | 12.8 | 6.4 | 149.1 |
| Apr | 13.8 | 17.0 | 10.7 | 127.3 |
| May | 17.4 | 20.5 | 14.8 | 135.8 |
| Jun | 20.2 | 23.0 | 17.9 | 166.2 |
| Jul | 23.5 | 26.6 | 21.2 | 128.3 |
| Aug | 25.5 | 28.6 | 23.3 | 94.9 |
| Sep | 23.4 | 25.9 | 21.3 | 216.3 |
| Oct | 19.2 | 21.5 | 16.8 | 272.5 |
| Nov | 14.4 | 17.3 | 11.1 | 133.2 |
| Dec | 9.3 | 12.7 | 5.7 | 92.9 |
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 Choshi changed on December 4, 2007; June 25, 2008; December 6, 2023 (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.