Ōtsuki weather in September
In September, Ōtsuki sees average daytime highs of 24°C and overnight lows near 17°C, with 249 mm of rain across 17.2 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 1st-wettest month of the year here.
Highs ease over the month, from about 26°C in the first days to 21°C by the end. The sky is clear or mostly clear about 15% of the time in September, and the air most often feels muggy.
Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Ōtsuki's 9th-clearest and 7th-windiest month. For the whole year in context, see Ōtsuki's year-round climate.
- Daytime high
- 24°
- 3rd warmest
- Overnight low
- 17°
- 10th coldest
- Rainfall
- 249 mm
- 17.2 wet days
- Daylight
- 12 h 12 min
- 5:32 AM – 5:45 PM
- Cloud cover
- 73%
- 9th clearest
- Wind
- 5 km/h
- 7th windiest
- Solar energy
- 3.73 kWh/m²
- Travel score
- 5.4
- out of 10
Ōtsuki is city in Yamanashi Prefecture, Japan.
- Density
- 86/km²
- people per km²
- Founded
- 1954
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Highs ease over the month, from about 26°C in the first days to 21°C by the end.
A typical September day in Ōtsuki reaches about 24°C in the afternoon and slips back to 17°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 28°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 24 | 24 | 24 | 24 | 24 | 23 | 23 | 23 | 23 | 23 | 22 | 22 | 22 | 22 | 22 | 22 | 21 | 21 | 21 |
| Avg low (°C) | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 19 | 18 | 18 | 18 | 18 | 18 | 18 | 17 | 17 | 17 | 17 | 17 | 16 | 16 | 16 | 16 | 15 | 15 | 15 | 15 | 15 | 15 | 14 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 26 | 19 |
| 2 | 26 | 19 |
| 3 | 26 | 19 |
| 4 | 26 | 19 |
| 5 | 26 | 19 |
| 6 | 25 | 19 |
| 7 | 25 | 19 |
| 8 | 25 | 19 |
| 9 | 25 | 18 |
| 10 | 25 | 18 |
| 11 | 25 | 18 |
| 12 | 24 | 18 |
| 13 | 24 | 18 |
| 14 | 24 | 18 |
| 15 | 24 | 17 |
| 16 | 24 | 17 |
| 17 | 23 | 17 |
| 18 | 23 | 17 |
| 19 | 23 | 17 |
| 20 | 23 | 16 |
| 21 | 23 | 16 |
| 22 | 22 | 16 |
| 23 | 22 | 16 |
| 24 | 22 | 15 |
| 25 | 22 | 15 |
| 26 | 22 | 15 |
| 27 | 22 | 15 |
| 28 | 21 | 15 |
| 29 | 21 | 15 |
| 30 | 21 | 14 |
How September really feels in Ōtsuki
Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Ōtsuki weather by month
How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 6° / -3° | 81 | 8.8 | 5.8 | 9.9 | 0.4 |
| Feb | 7° / -3° | 87 | 9.9 | 6.2 | 10.7 | 0.7 |
| Mar | 10° / 1° | 158 | 15.1 | 5.1 | 11.7 | 2.0 |
| Apr | 16° / 6° | 158 | 14.3 | 0.8 | 12.9 | 4.2 |
| May | 20° / 11° | 168 | 14.9 | 0 | 13.9 | 5.4 |
| Jun | 23° / 16° | 229 | 18.4 | 0 | 14.4 | 5.0 |
| Jul | 27° / 20° | 230 | 19.8 | 0 | 14.2 | 4.9 |
| Aug | 27° / 21° | 187 | 19.1 | 0 | 13.3 | 5.0 |
| Sep | 24° / 17° | 249 | 17.2 | 0 | 12.2 | 5.4 |
| Oct | 18° / 11° | 246 | 15.3 | 0 | 11.1 | 5.1 |
| Nov | 13° / 5° | 113 | 11.3 | 0.1 | 10.1 | 3.7 |
| Dec | 9° / 1° | 78 | 9.3 | 2.3 | 9.6 | 1.7 |
Cloud cover in September
The sky is clear or mostly clear about 15% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 70%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 32 | 32 | 32 | 32 | 32 | 31 | 31 | 31 | 31 | 31 | 31 | 30 | 30 | 29 | 29 | 29 | 29 | 29 | 28 | 28 | 28 | 28 | 27 | 28 | 28 | 28 | 28 | 29 | 29 | 29 |
| Cloudier (%) | 68 | 68 | 68 | 68 | 68 | 69 | 69 | 69 | 69 | 69 | 69 | 70 | 70 | 71 | 71 | 71 | 71 | 71 | 72 | 72 | 72 | 72 | 73 | 72 | 72 | 72 | 72 | 71 | 71 | 71 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 32 | 68 |
| 2 | 32 | 68 |
| 3 | 32 | 68 |
| 4 | 32 | 68 |
| 5 | 32 | 68 |
| 6 | 31 | 69 |
| 7 | 31 | 69 |
| 8 | 31 | 69 |
| 9 | 31 | 69 |
| 10 | 31 | 69 |
| 11 | 31 | 69 |
| 12 | 30 | 70 |
| 13 | 30 | 70 |
| 14 | 29 | 71 |
| 15 | 29 | 71 |
| 16 | 29 | 71 |
| 17 | 29 | 71 |
| 18 | 29 | 71 |
| 19 | 28 | 72 |
| 20 | 28 | 72 |
| 21 | 28 | 72 |
| 22 | 28 | 72 |
| 23 | 27 | 73 |
| 24 | 28 | 72 |
| 25 | 28 | 72 |
| 26 | 28 | 72 |
| 27 | 28 | 72 |
| 28 | 29 | 71 |
| 29 | 29 | 71 |
| 30 | 29 | 71 |
Chance of precipitation in September
Ōtsuki gets around 249 mm of rain over 17.2 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 58% and peaks near 60% on the wettest days.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 59 | 59 | 59 | 59 | 59 | 60 | 60 | 60 | 59 | 59 | 59 | 58 | 58 | 58 | 57 | 57 | 57 | 57 | 57 | 56 | 56 | 56 | 56 | 56 | 56 | 56 | 56 | 56 | 56 | 56 |
| Rain chance (%) | |
|---|---|
| 1 | 59 |
| 2 | 59 |
| 3 | 59 |
| 4 | 59 |
| 5 | 59 |
| 6 | 60 |
| 7 | 60 |
| 8 | 60 |
| 9 | 59 |
| 10 | 59 |
| 11 | 59 |
| 12 | 58 |
| 13 | 58 |
| 14 | 58 |
| 15 | 57 |
| 16 | 57 |
| 17 | 57 |
| 18 | 57 |
| 19 | 57 |
| 20 | 56 |
| 21 | 56 |
| 22 | 56 |
| 23 | 56 |
| 24 | 56 |
| 25 | 56 |
| 26 | 56 |
| 27 | 56 |
| 28 | 56 |
| 29 | 56 |
| 30 | 56 |
Humidity in September
Most of September feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the muggy band about 33% of days. Sticky, muggy-or-worse air turns up on roughly 37% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 4 | 5 | 6 | 8 | 9 | 11 | 12 | 14 | 16 | 17 | 19 | 21 | 22 | 24 | 26 | 27 | 29 | 30 | 32 |
| Comfortable (%) | 6 | 6 | 7 | 8 | 8 | 10 | 11 | 12 | 14 | 15 | 16 | 18 | 19 | 21 | 22 | 23 | 25 | 26 | 27 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 38 |
| Humid (%) | 25 | 26 | 26 | 27 | 28 | 29 | 29 | 30 | 30 | 31 | 31 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 31 | 31 | 31 | 30 | 30 | 29 | 28 | 28 | 27 | 26 | 24 | 23 |
| Muggy (%) | 57 | 57 | 57 | 56 | 54 | 52 | 52 | 51 | 48 | 47 | 45 | 43 | 41 | 38 | 36 | 34 | 31 | 29 | 26 | 24 | 21 | 19 | 17 | 15 | 13 | 11 | 10 | 8 | 7 | 6 |
| Oppressive (%) | 12 | 11 | 10 | 9 | 9 | 8 | 7 | 6 | 6 | 5 | 5 | 4 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | |
|---|---|---|---|---|---|
| 1 | 0 | 6 | 25 | 57 | 12 |
| 2 | 0 | 6 | 26 | 57 | 11 |
| 3 | 0 | 7 | 26 | 57 | 10 |
| 4 | 0 | 8 | 27 | 56 | 9 |
| 5 | 1 | 8 | 28 | 54 | 9 |
| 6 | 1 | 10 | 29 | 52 | 8 |
| 7 | 1 | 11 | 29 | 52 | 7 |
| 8 | 1 | 12 | 30 | 51 | 6 |
| 9 | 2 | 14 | 30 | 48 | 6 |
| 10 | 2 | 15 | 31 | 47 | 5 |
| 11 | 3 | 16 | 31 | 45 | 5 |
| 12 | 4 | 18 | 32 | 43 | 4 |
| 13 | 5 | 19 | 32 | 41 | 3 |
| 14 | 6 | 21 | 32 | 38 | 3 |
| 15 | 8 | 22 | 32 | 36 | 2 |
| 16 | 9 | 23 | 32 | 34 | 2 |
| 17 | 11 | 25 | 32 | 31 | 2 |
| 18 | 12 | 26 | 32 | 29 | 1 |
| 19 | 14 | 27 | 31 | 26 | 1 |
| 20 | 16 | 29 | 31 | 24 | 1 |
| 21 | 17 | 30 | 31 | 21 | 1 |
| 22 | 19 | 31 | 30 | 19 | 1 |
| 23 | 21 | 32 | 30 | 17 | 1 |
| 24 | 22 | 33 | 29 | 15 | 0 |
| 25 | 24 | 34 | 28 | 13 | 0 |
| 26 | 26 | 35 | 28 | 11 | 0 |
| 27 | 27 | 36 | 27 | 10 | 0 |
| 28 | 29 | 37 | 26 | 8 | 0 |
| 29 | 30 | 38 | 24 | 7 | 0 |
| 30 | 32 | 38 | 23 | 6 | 0 |
Wind in September
Winds average 5 km/h in September.
Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 5 | calm |
| 2 | 5 | calm |
| 3 | 5 | calm |
| 4 | 5 | calm |
| 5 | 5 | calm |
| 6 | 5 | calm |
| 7 | 5 | calm |
| 8 | 5 | calm |
| 9 | 5 | calm |
| 10 | 5 | calm |
| 11 | 5 | calm |
| 12 | 5 | calm |
| 13 | 5 | calm |
| 14 | 5 | calm |
| 15 | 5 | calm |
| 16 | 5 | calm |
| 17 | 5 | calm |
| 18 | 5 | calm |
| 19 | 5 | calm |
| 20 | 5 | calm |
| 21 | 5 | calm |
| 22 | 5 | calm |
| 23 | 5 | calm |
| 24 | 5 | calm |
| 25 | 5 | calm |
| 26 | 5 | calm |
| 27 | 5 | calm |
| 28 | 5 | calm |
| 29 | 5 | calm |
| 30 | 5 | calm |
Sunrise & sunset in September
Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 66 minutes over September. Sunrise moves from 5:20 AM to 5:43 AM, and sunset from 6:08 PM to 5:24 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.8 | 12.8 | 12.7 | 12.7 | 12.6 | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.3 | 12.3 | 12.3 | 12.2 | 12.2 | 12.1 | 12.1 | 12.1 | 12.0 | 12.0 | 12.0 | 11.9 | 11.9 | 11.8 | 11.8 | 11.8 | 11.7 | 11.7 |
| Sunrise (AM) | 5:20 | 5:21 | 5:22 | 5:22 | 5:23 | 5:24 | 5:25 | 5:26 | 5:26 | 5:27 | 5:28 | 5:29 | 5:29 | 5:30 | 5:31 | 5:32 | 5:33 | 5:33 | 5:34 | 5:35 | 5:36 | 5:36 | 5:37 | 5:38 | 5:39 | 5:40 | 5:40 | 5:41 | 5:42 | 5:43 |
| Sunset (PM) | 6:08 | 6:06 | 6:05 | 6:03 | 6:02 | 6:00 | 5:59 | 5:57 | 5:56 | 5:54 | 5:53 | 5:51 | 5:50 | 5:48 | 5:47 | 5:45 | 5:44 | 5:42 | 5:40 | 5:39 | 5:37 | 5:36 | 5:34 | 5:33 | 5:31 | 5:30 | 5:28 | 5:27 | 5:25 | 5:24 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.8 | 5:20 | 6:08 |
| 2 | 12.8 | 5:21 | 6:06 |
| 3 | 12.7 | 5:22 | 6:05 |
| 4 | 12.7 | 5:22 | 6:03 |
| 5 | 12.6 | 5:23 | 6:02 |
| 6 | 12.6 | 5:24 | 6:00 |
| 7 | 12.6 | 5:25 | 5:59 |
| 8 | 12.5 | 5:26 | 5:57 |
| 9 | 12.5 | 5:26 | 5:56 |
| 10 | 12.5 | 5:27 | 5:54 |
| 11 | 12.4 | 5:28 | 5:53 |
| 12 | 12.4 | 5:29 | 5:51 |
| 13 | 12.3 | 5:29 | 5:50 |
| 14 | 12.3 | 5:30 | 5:48 |
| 15 | 12.3 | 5:31 | 5:47 |
| 16 | 12.2 | 5:32 | 5:45 |
| 17 | 12.2 | 5:33 | 5:44 |
| 18 | 12.1 | 5:33 | 5:42 |
| 19 | 12.1 | 5:34 | 5:40 |
| 20 | 12.1 | 5:35 | 5:39 |
| 21 | 12.0 | 5:36 | 5:37 |
| 22 | 12.0 | 5:36 | 5:36 |
| 23 | 12.0 | 5:37 | 5:34 |
| 24 | 11.9 | 5:38 | 5:33 |
| 25 | 11.9 | 5:39 | 5:31 |
| 26 | 11.8 | 5:40 | 5:30 |
| 27 | 11.8 | 5:40 | 5:28 |
| 28 | 11.8 | 5:41 | 5:27 |
| 29 | 11.7 | 5:42 | 5:25 |
| 30 | 11.7 | 5:43 | 5:24 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 3.73 kWh/m².
For context, solar energy here swings from a low near 2.41 kWh/m² to a high of 5.16 kWh/m² in May across the year — September's 3.73 kWh/m² falls in the middle.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 4.3 | 4.2 | 4.2 | 4.1 | 4.1 | 4.1 | 4.0 | 4.0 | 4.0 | 3.9 | 3.9 | 3.8 | 3.8 | 3.8 | 3.7 | 3.7 | 3.7 | 3.6 | 3.6 | 3.5 | 3.5 | 3.5 | 3.5 | 3.4 | 3.4 | 3.4 | 3.3 | 3.3 | 3.3 | 3.2 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.3 | Bright |
| 2 | 4.2 | Bright |
| 3 | 4.2 | Bright |
| 4 | 4.1 | Bright |
| 5 | 4.1 | Bright |
| 6 | 4.1 | Bright |
| 7 | 4.0 | Bright |
| 8 | 4.0 | Moderate |
| 9 | 4.0 | Moderate |
| 10 | 3.9 | Moderate |
| 11 | 3.9 | Moderate |
| 12 | 3.8 | Moderate |
| 13 | 3.8 | Moderate |
| 14 | 3.8 | Moderate |
| 15 | 3.7 | Moderate |
| 16 | 3.7 | Moderate |
| 17 | 3.7 | Moderate |
| 18 | 3.6 | Moderate |
| 19 | 3.6 | Moderate |
| 20 | 3.5 | Moderate |
| 21 | 3.5 | Moderate |
| 22 | 3.5 | Moderate |
| 23 | 3.5 | Moderate |
| 24 | 3.4 | Moderate |
| 25 | 3.4 | Moderate |
| 26 | 3.4 | Moderate |
| 27 | 3.3 | Moderate |
| 28 | 3.3 | Moderate |
| 29 | 3.3 | Moderate |
| 30 | 3.2 | Moderate |
Hazard calendar for Ōtsuki
In September, Ōtsuki sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Ōtsuki sits in the Pacific typhoon belt; the season peaks July–October.
Is September a good time to visit Ōtsuki?
Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
September is a reasonable time to visit Ōtsuki for sightseeing.
What to pack for Ōtsuki in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Ōtsuki sees daytime highs around 24°C and nights near 17°C. Pack rain gear. Worth having: light clothes. About 17 days see rain.
Sea temperature near Ōtsuki in September
The nearest coast averages about 25°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 57 km away) is warmest in August at about 26°C and coldest in February near 15°C.
It's comfortable for a long swim from May 31 to Nov 26 — about 5.9 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 15 | 16 | 17 | 19 | 21 | 24 | 26 | 25 | 23 | 21 | 18 |
| Comfort | Cool | Cool | Cool | Cool | Cool | Refreshing | Refreshing | Warm | Warm | Refreshing | Refreshing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 15 | Cool |
| Mar | 16 | Cool |
| Apr | 17 | Cool |
| May | 19 | Cool |
| Jun | 21 | Refreshing |
| Jul | 24 | Refreshing |
| Aug | 26 | Warm |
| Sep | 25 | Warm |
| Oct | 23 | Refreshing |
| Nov | 21 | Refreshing |
| Dec | 18 | Cool |
UV index in Ōtsuki in September
Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Ōtsuki peaks around July 16 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 3 | 4 | 6 | 7 | 9 | 10 | 11 | 10 | 9 | 6 | 4 | 2 |
| Level | Moderate | Moderate | High | Very high | Very high | Very high | Extreme | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 4 | Moderate |
| Mar | 6 | High |
| Apr | 7 | Very high |
| May | 9 | Very high |
| Jun | 10 | Very high |
| Jul | 11 | Extreme |
| Aug | 10 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 2 | Moderate |
Air quality in Ōtsuki in September
Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.
Air quality in Ōtsuki is worst in April — around 23 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (December, 10 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 12 | 20 | 20 | 23 | 20 | 17 | 13 | 12 | 12 | 12 | 11 | 10 |
| Level | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 12 | Good |
| Feb | 20 | Moderate |
| Mar | 20 | Moderate |
| Apr | 23 | Moderate |
| May | 20 | Moderate |
| Jun | 17 | Moderate |
| Jul | 13 | Moderate |
| Aug | 12 | Good |
| Sep | 12 | Good |
| Oct | 12 | Good |
| Nov | 11 | Good |
| Dec | 10 | Good |
Where is Ōtsuki?
Ōtsuki sits at 35.6°N, 139.0°E, 360 m above sea level, in Japan. The nearest listed city is Tsuru, 10 km away.
Topography around Ōtsuki
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ōtsuki.
Within 3 km, the terrain around Ōtsuki has large variations in elevation — a maximum elevation change of 737 m around an average of 476 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,836 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,737 m.
The land around Ōtsuki is covered by trees (82%) within 3 km, trees (94%) within 16 km, and trees (60%) and artificial surfaces (20%) within 80 km.
Japan travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 100 V · 50 / 60 Hz
- Prices
- ≈ 65% of US
- price level, 2025
- GDP per capita
- $35,951
- 2025
- Happiness
- 6.1 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.2
- per 100k, 2023
- Road deaths
- 3.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Very low
- EF EPI 446
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Ōtsuki (35.6185°, 138.974°, elevation 360 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).