Jōetsu weather in June
In June, Jōetsu has daytime highs averaging 24 °C, nights around 17 °C, with 17 wet days, and a sea temperature of 20 °C. Figures are 1991–2020 climate normals.
- 24.3°C Average high
- 16.8°C Average low
- 17days Wet days
- 164mm Rainfall
- 19.6°C Sea temperature
- 15h Daylight
Daily temperatures through June
How June develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 June | 23.4 °C | 15.0 °C | 41 % |
| 11–20 June | 24.3 °C | 16.8 °C | 59 % |
| 21–30 June | 25.3 °C | 18.5 °C | 66 % |
- Average highs rise from 23.4 °C early in June to 25.3 °C by the end of it.
- Rain is most likely over days 21–30 of June (66 % of days) and least likely over days 1–10 (41 %).
What to expect
| Measure | Typical June | Share of the month |
|---|---|---|
| Days above 25 °C | 12 of 30 | 41 % |
| Days above 30 °C | 0.5 of 30 | 2 % |
| Days below 0 °C | 0 of 30 | 0 % |
| Days with more than 1 mm rain | 17 of 30 | 55 % |
Conditions in June
| Measure | Average |
|---|---|
| Mean temperature | 20 °C |
| Record high (1991–2020) | 32 °C |
| Record low (1991–2020) | 8.5 °C |
| Relative humidity | 83 % |
| Wind speed | 11 km/h |
| Cloud cover | 78 % |
June compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| April | 15.1 °C | 116 mm | 63 % |
| May | 21.0 °C | 126 mm | 66 % |
| June | 24.3 °C | 164 mm | 78 % |
| July | 27.7 °C | 240 mm | 77 % |
| August | 29.2 °C | 196 mm | 67 % |
See all twelve months for Jōetsu
- June is the 4th warmest month here.
- It is the 4th driest month of the year.
- It ranks 12th for least cloud cover.
- Days last about 15 hours from sunrise to sunset.
- It rains on 17 of 30 days — 55 % of the month.
- Nights are about 7.5 °C cooler than the middle of the day.
- The hottest June day on record since 1991 reached 32 °C, 7.9 °C above the usual daytime high.
- Beach score: 56 / 100 — see how this is calculated.
QuestionsJune in Jōetsu, answered
How warm is Jōetsu in June?
Daily highs average 24 °C and nights fall to about 17 °C, a spread of 7.5 °C between afternoon and dawn. That makes June the 4th warmest month of the year here.
Does it rain much in Jōetsu in June?
June averages 164 mm of rain, spread over about 17 of the 30 days — 55 % of the month. Cloud cover averages 78 % of the sky.
Is the sea warm enough to swim in June?
The sea averages 20 °C off Jōetsu in June. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in June?
Jōetsu averages 15 hours between sunrise and sunset in June. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
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
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. 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.