Chiba climate
Chiba is warmest in August, with average highs of 30 °C, and coldest in January, when nights average 2.0 °C. October is the wettest month (242 mm) and December the driest (79 mm). Figures are 1991–2020 climate normals.
Across a full year Chiba averages 1,709 mm of rain, 92 days above 25 °C and 13 days below freezing.
Japan · population 979,768 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 30 °C
- Coldest month January 2.0 °C
- Driest month December 79 mm
- Wettest month October 242 mm
- Least cloud January 46 % cloud
- Hottest on record July 36 °C
- Coldest on record January -8.1 °C
- Warmest sea August 26 °C
What to expectChiba through the year
Chiba has a clear annual cycle: average daily highs run from 8.6 °C in January to 30 °C in August, a swing of 21 °C in mean temperature across the year.
Counted across a normal year, 92 days a year reach 25 °C, 26 of them reach 30 °C, 13 nights drop below freezing. The warmest reading in the 1991–2020 record is 36 °C, in July.
Rain is strongly seasonal. October averages 242 mm against 79 mm in December — 3.1 times as much. Planning around the dry months matters more here than planning around temperature.
The sea off Chiba is warmest in August at 26 °C and coldest in February at 13 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 8.6 °C | 87 mm | 46 % |
| February | 9.4 °C | 85 mm | 54 % |
| March | 12.5 °C | 143 mm | 60 % |
| April | 17.3 °C | 136 mm | 63 % |
| May | 21.6 °C | 147 mm | 69 % |
| June | 24.5 °C | 189 mm | 80 % |
| July | 28.2 °C | 154 mm | 73 % |
| August | 29.6 °C | 118 mm | 62 % |
| September | 26.2 °C | 208 mm | 66 % |
| October | 21.0 °C | 242 mm | 63 % |
| November | 16.0 °C | 122 mm | 58 % |
| December | 11.1 °C | 79 mm | 49 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 8.6 °C | 2.0 °C | 5.1 °C | 17.5 °C | -8.1 °C | 0 | 0 | 6 |
| February | 9.4 °C | 2.4 °C | 5.7 °C | 21.6 °C | -6.1 °C | 0 | 0 | 5 |
| March | 12.5 °C | 5.5 °C | 8.9 °C | 22.3 °C | -2.3 °C | 0 | 0 | 1 |
| April | 17.3 °C | 10.3 °C | 13.6 °C | 25.3 °C | 2.1 °C | 0 | 0 | 0 |
| May | 21.6 °C | 15.0 °C | 18.0 °C | 29.3 °C | 6.8 °C | 3 | 0 | 0 |
| June | 24.5 °C | 18.8 °C | 21.3 °C | 32.3 °C | 11.6 °C | 12 | 0 | 0 |
| July | 28.2 °C | 22.6 °C | 25.0 °C | 36.3 °C | 14.7 °C | 26 | 9 | 0 |
| August | 29.6 °C | 23.9 °C | 26.3 °C | 35.7 °C | 18.1 °C | 29 | 14 | 0 |
| September | 26.2 °C | 20.9 °C | 23.2 °C | 34.2 °C | 12.3 °C | 19 | 3 | 0 |
| October | 21.0 °C | 15.6 °C | 18.0 °C | 29.4 °C | 7.8 °C | 3 | 0 | 0 |
| November | 16.0 °C | 10.0 °C | 12.9 °C | 23.2 °C | 2.2 °C | 0 | 0 | 0 |
| December | 11.1 °C | 4.7 °C | 7.7 °C | 21.9 °C | -2.3 °C | 0 | 0 | 1 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind | Sea temp |
|---|---|---|---|---|---|---|---|
| January | 87 mm | 8 | 10 h/day | 46 % | 70 % | 25 km/h | 13.6 °C |
| February | 85 mm | 9 | 11 h/day | 54 % | 70 % | 25 km/h | 12.5 °C |
| March | 143 mm | 13 | 12 h/day | 60 % | 72 % | 26 km/h | 13.2 °C |
| April | 136 mm | 12 | 13 h/day | 63 % | 75 % | 26 km/h | 15.0 °C |
| May | 147 mm | 12 | 14 h/day | 69 % | 78 % | 24 km/h | 17.9 °C |
| June | 189 mm | 15 | 15 h/day | 80 % | 83 % | 22 km/h | 20.9 °C |
| July | 154 mm | 12 | 14 h/day | 73 % | 84 % | 22 km/h | 23.4 °C |
| August | 118 mm | 11 | 14 h/day | 62 % | 82 % | 21 km/h | 25.9 °C |
| September | 208 mm | 15 | 12 h/day | 66 % | 82 % | 22 km/h | 24.7 °C |
| October | 242 mm | 14 | 11 h/day | 63 % | 80 % | 22 km/h | 21.6 °C |
| November | 122 mm | 11 | 10 h/day | 58 % | 78 % | 22 km/h | 18.9 °C |
| December | 79 mm | 8 | 9.8 h/day | 49 % | 73 % | 24 km/h | 16.0 °C |
Planning a trip? See the best time to visit Chiba.
QuestionsCommon questions about Chiba’s climate
When is the best time to visit Chiba?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, August is the warmest month and December the driest. The month-by-month table above has the full picture.
How hot does Chiba get?
In August, the warmest month, daily highs average 30 °C. About 26 days a year pass 30 °C. The highest value in the 1991–2020 record is 36 °C.
How cold does it get in winter?
Nights average 2.0 °C in January, the coldest month. A normal year has 13 nights below freezing.
Which month is wettest in Chiba?
October, averaging 242 mm over 14 days with rain. The driest month is December with 79 mm. The year as a whole averages 1,709 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Chiba rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Data point
- 35.600°, 140.117° (the coordinates the reanalysis values are taken for)
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.