Unzen weather in September
In September, Unzen sees average daytime highs of 29°C and overnight lows near 22°C, with 203 mm of rain across 12.4 wet days and about 12.2 hours of daylight. It is the 3rd-warmest and 3rd-wettest month of the year here.
Highs ease over the month, from about 31°C in the first days to 27°C by the end. The sky is clear or mostly clear about 36% of the time in September, and the air most often feels oppressive.
Daylight stretches from about 12 h 42 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Unzen's 4th-clearest and 9th-windiest month. For the whole year in context, see Unzen's year-round climate.
- Daytime high
- 29°
- 3rd warmest
- Overnight low
- 22°
- 10th coldest
- Rainfall
- 203 mm
- 12.4 wet days
- Daylight
- 12 h 12 min
- 6:07 AM – 6:19 PM
- Cloud cover
- 59%
- 4th clearest
- Wind
- 9 km/h
- 9th windiest
- Solar energy
- 4.32 kWh/m²
- Travel score
- 5.3
- out of 10
Temperature in September
Highs ease over the month, from about 31°C in the first days to 27°C by the end.
A typical September day in Unzen reaches about 29°C in the afternoon and slips back to 22°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 32°C. Set against its neighbours, September runs about 3°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) | 31 | 31 | 31 | 31 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 29 | 29 | 29 | 29 | 29 | 29 | 29 | 28 | 28 | 28 | 28 | 28 | 28 | 27 | 27 | 27 | 27 | 27 |
| Avg low (°C) | 24 | 24 | 24 | 24 | 24 | 24 | 23 | 23 | 23 | 23 | 23 | 23 | 23 | 22 | 22 | 22 | 22 | 22 | 22 | 21 | 21 | 21 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 31 | 24 |
| 2 | 31 | 24 |
| 3 | 31 | 24 |
| 4 | 31 | 24 |
| 5 | 30 | 24 |
| 6 | 30 | 24 |
| 7 | 30 | 23 |
| 8 | 30 | 23 |
| 9 | 30 | 23 |
| 10 | 30 | 23 |
| 11 | 30 | 23 |
| 12 | 30 | 23 |
| 13 | 29 | 23 |
| 14 | 29 | 22 |
| 15 | 29 | 22 |
| 16 | 29 | 22 |
| 17 | 29 | 22 |
| 18 | 29 | 22 |
| 19 | 29 | 22 |
| 20 | 28 | 21 |
| 21 | 28 | 21 |
| 22 | 28 | 21 |
| 23 | 28 | 21 |
| 24 | 28 | 21 |
| 25 | 28 | 21 |
| 26 | 27 | 20 |
| 27 | 27 | 20 |
| 28 | 27 | 20 |
| 29 | 27 | 20 |
| 30 | 27 | 20 |
How September really feels in Unzen
Once humidity and wind are folded in, September averages 10 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.
The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Unzen weather by month
How September compares with the rest of the year at a glance. September is the 3rd-warmest and 3rd-wettest month here — the current month is highlighted below.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 11° / 5° | 70 | 7.7 | 10.1 | 2.7 |
| Feb | 12° / 5° | 88 | 9 | 10.8 | 3.2 |
| Mar | 15° / 8° | 134 | 11.6 | 11.8 | 4.6 |
| Apr | 20° / 12° | 151 | 10.9 | 12.8 | 6.1 |
| May | 24° / 16° | 182 | 11.1 | 13.7 | 6.6 |
| Jun | 27° / 21° | 429 | 17 | 14.1 | 5.2 |
| Jul | 30° / 24° | 348 | 18.5 | 13.9 | 3.7 |
| Aug | 32° / 25° | 179 | 14.5 | 13.2 | 3.5 |
| Sep | 29° / 22° | 203 | 12.4 | 12.2 | 5.3 |
| Oct | 24° / 17° | 112 | 7.9 | 11.2 | 7.3 |
| Nov | 18° / 12° | 102 | 8.4 | 10.3 | 6.2 |
| Dec | 13° / 7° | 81 | 7.6 | 9.9 | 3.9 |
Cloud cover in September
The sky is clear or mostly clear about 36% 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 50%. Skies tend to open up as the month goes on.
| 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 (%) | 45 | 47 | 47 | 47 | 46 | 47 | 47 | 47 | 48 | 48 | 49 | 50 | 51 | 52 | 51 | 51 | 51 | 51 | 51 | 52 | 52 | 52 | 52 | 52 | 52 | 52 | 53 | 53 | 52 | 53 |
| Cloudier (%) | 55 | 53 | 53 | 53 | 54 | 53 | 53 | 53 | 52 | 52 | 51 | 50 | 49 | 48 | 49 | 49 | 49 | 49 | 49 | 48 | 48 | 48 | 48 | 48 | 48 | 48 | 47 | 47 | 48 | 47 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 45 | 55 |
| 2 | 47 | 53 |
| 3 | 47 | 53 |
| 4 | 47 | 53 |
| 5 | 46 | 54 |
| 6 | 47 | 53 |
| 7 | 47 | 53 |
| 8 | 47 | 53 |
| 9 | 48 | 52 |
| 10 | 48 | 52 |
| 11 | 49 | 51 |
| 12 | 50 | 50 |
| 13 | 51 | 49 |
| 14 | 52 | 48 |
| 15 | 51 | 49 |
| 16 | 51 | 49 |
| 17 | 51 | 49 |
| 18 | 51 | 49 |
| 19 | 51 | 49 |
| 20 | 52 | 48 |
| 21 | 52 | 48 |
| 22 | 52 | 48 |
| 23 | 52 | 48 |
| 24 | 52 | 48 |
| 25 | 52 | 48 |
| 26 | 52 | 48 |
| 27 | 53 | 47 |
| 28 | 53 | 47 |
| 29 | 52 | 48 |
| 30 | 53 | 47 |
Chance of precipitation in September
Unzen gets around 203 mm of rain over 12.4 wet days in September. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 40% and peaks near 49% on the wettest days. The odds ease toward the end of the month.
| 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 (%) | 49 | 48 | 48 | 47 | 47 | 46 | 46 | 45 | 44 | 44 | 43 | 42 | 41 | 41 | 40 | 40 | 39 | 38 | 38 | 37 | 37 | 36 | 36 | 35 | 35 | 34 | 34 | 34 | 33 | 33 |
| Rain chance (%) | |
|---|---|
| 1 | 49 |
| 2 | 48 |
| 3 | 48 |
| 4 | 47 |
| 5 | 47 |
| 6 | 46 |
| 7 | 46 |
| 8 | 45 |
| 9 | 44 |
| 10 | 44 |
| 11 | 43 |
| 12 | 42 |
| 13 | 41 |
| 14 | 41 |
| 15 | 40 |
| 16 | 40 |
| 17 | 39 |
| 18 | 38 |
| 19 | 38 |
| 20 | 37 |
| 21 | 37 |
| 22 | 36 |
| 23 | 36 |
| 24 | 35 |
| 25 | 35 |
| 26 | 34 |
| 27 | 34 |
| 28 | 34 |
| 29 | 33 |
| 30 | 33 |
Humidity in September
Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, September lands in the oppressive band about 32% of days. Sticky, muggy-or-worse air turns up on roughly 67% 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 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | 4 | 4 | 5 | 5 | 6 | 6 | 7 | 8 | 8 | 9 | 9 | 10 | 11 | 12 |
| Comfortable (%) | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 3 | 4 | 5 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| Humid (%) | 6 | 7 | 8 | 9 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 21 | 22 | 23 | 24 | 25 | 25 | 26 | 27 | 27 | 28 | 28 | 29 | 29 | 29 | 29 |
| Muggy (%) | 21 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 30 | 30 | 31 | 31 | 31 | 31 | 30 | 30 | 30 | 29 | 29 | 29 | 28 | 28 | 28 | 27 | 27 | 26 | 25 | 25 | 24 |
| Oppressive (%) | 54 | 52 | 51 | 50 | 49 | 48 | 47 | 45 | 44 | 42 | 40 | 38 | 36 | 34 | 32 | 31 | 29 | 27 | 25 | 24 | 22 | 21 | 19 | 18 | 16 | 15 | 14 | 13 | 12 | 11 |
| Miserable (%) | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 9 | 8 | 8 | 7 | 7 | 6 | 6 | 5 | 5 | 4 | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 2 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 1 | 6 | 21 | 54 | 18 |
| 2 | 0 | 1 | 7 | 23 | 52 | 17 |
| 3 | 0 | 1 | 8 | 24 | 51 | 16 |
| 4 | 0 | 1 | 9 | 25 | 50 | 15 |
| 5 | 0 | 1 | 9 | 26 | 49 | 14 |
| 6 | 0 | 2 | 10 | 27 | 48 | 13 |
| 7 | 0 | 2 | 11 | 28 | 47 | 12 |
| 8 | 0 | 2 | 12 | 29 | 45 | 11 |
| 9 | 1 | 3 | 13 | 30 | 44 | 10 |
| 10 | 1 | 4 | 14 | 30 | 42 | 9 |
| 11 | 1 | 5 | 15 | 30 | 40 | 9 |
| 12 | 1 | 5 | 16 | 31 | 38 | 8 |
| 13 | 2 | 6 | 17 | 31 | 36 | 8 |
| 14 | 2 | 7 | 18 | 31 | 34 | 7 |
| 15 | 3 | 8 | 19 | 31 | 32 | 7 |
| 16 | 3 | 9 | 21 | 30 | 31 | 6 |
| 17 | 4 | 10 | 22 | 30 | 29 | 6 |
| 18 | 4 | 11 | 23 | 30 | 27 | 5 |
| 19 | 5 | 12 | 24 | 29 | 25 | 5 |
| 20 | 5 | 13 | 25 | 29 | 24 | 4 |
| 21 | 6 | 14 | 25 | 29 | 22 | 4 |
| 22 | 6 | 15 | 26 | 28 | 21 | 4 |
| 23 | 7 | 16 | 27 | 28 | 19 | 3 |
| 24 | 8 | 17 | 27 | 28 | 18 | 3 |
| 25 | 8 | 18 | 28 | 27 | 16 | 3 |
| 26 | 9 | 19 | 28 | 27 | 15 | 3 |
| 27 | 9 | 20 | 29 | 26 | 14 | 3 |
| 28 | 10 | 21 | 29 | 25 | 13 | 2 |
| 29 | 11 | 22 | 29 | 25 | 12 | 2 |
| 30 | 12 | 23 | 29 | 24 | 11 | 2 |
Wind in September
Winds average 9 km/h in September.
Across September, daily wind ranges from about 9 km/h on the calmest days to 9 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) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 |
| 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 | 9 | calm |
| 2 | 9 | calm |
| 3 | 9 | calm |
| 4 | 9 | calm |
| 5 | 9 | calm |
| 6 | 9 | calm |
| 7 | 9 | calm |
| 8 | 9 | calm |
| 9 | 9 | calm |
| 10 | 9 | calm |
| 11 | 9 | calm |
| 12 | 9 | calm |
| 13 | 9 | calm |
| 14 | 9 | calm |
| 15 | 9 | calm |
| 16 | 9 | calm |
| 17 | 9 | calm |
| 18 | 9 | calm |
| 19 | 9 | calm |
| 20 | 9 | calm |
| 21 | 9 | calm |
| 22 | 9 | calm |
| 23 | 9 | calm |
| 24 | 9 | calm |
| 25 | 9 | calm |
| 26 | 9 | calm |
| 27 | 9 | calm |
| 28 | 9 | calm |
| 29 | 9 | calm |
| 30 | 9 | calm |
Sunrise & sunset in September
Daylight runs from about 12 h 42 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 60 minutes over September. Sunrise moves from 5:57 AM to 6:17 AM, and sunset from 6:40 PM to 6:00 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) | 12.7 | 12.7 | 12.6 | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.4 | 12.3 | 12.3 | 12.3 | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 12.1 | 12.0 | 12.0 | 12.0 | 11.9 | 11.9 | 11.9 | 11.8 | 11.8 | 11.7 | 11.7 |
| Sunrise (AM) | 5:57 | 5:58 | 5:59 | 5:59 | 6:00 | 6:01 | 6:01 | 6:02 | 6:03 | 6:03 | 6:04 | 6:05 | 6:05 | 6:06 | 6:07 | 6:07 | 6:08 | 6:09 | 6:09 | 6:10 | 6:11 | 6:11 | 6:12 | 6:13 | 6:13 | 6:14 | 6:15 | 6:15 | 6:16 | 6:17 |
| Sunset (PM) | 6:40 | 6:39 | 6:37 | 6:36 | 6:35 | 6:33 | 6:32 | 6:30 | 6:29 | 6:28 | 6:26 | 6:25 | 6:24 | 6:22 | 6:21 | 6:19 | 6:18 | 6:16 | 6:15 | 6:14 | 6:12 | 6:11 | 6:09 | 6:08 | 6:07 | 6:05 | 6:04 | 6:03 | 6:01 | 6:00 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.7 | 5:57 | 6:40 |
| 2 | 12.7 | 5:58 | 6:39 |
| 3 | 12.6 | 5:59 | 6:37 |
| 4 | 12.6 | 5:59 | 6:36 |
| 5 | 12.6 | 6:00 | 6:35 |
| 6 | 12.5 | 6:01 | 6:33 |
| 7 | 12.5 | 6:01 | 6:32 |
| 8 | 12.5 | 6:02 | 6:30 |
| 9 | 12.4 | 6:03 | 6:29 |
| 10 | 12.4 | 6:03 | 6:28 |
| 11 | 12.4 | 6:04 | 6:26 |
| 12 | 12.3 | 6:05 | 6:25 |
| 13 | 12.3 | 6:05 | 6:24 |
| 14 | 12.3 | 6:06 | 6:22 |
| 15 | 12.2 | 6:07 | 6:21 |
| 16 | 12.2 | 6:07 | 6:19 |
| 17 | 12.2 | 6:08 | 6:18 |
| 18 | 12.1 | 6:09 | 6:16 |
| 19 | 12.1 | 6:09 | 6:15 |
| 20 | 12.1 | 6:10 | 6:14 |
| 21 | 12.0 | 6:11 | 6:12 |
| 22 | 12.0 | 6:11 | 6:11 |
| 23 | 12.0 | 6:12 | 6:09 |
| 24 | 11.9 | 6:13 | 6:08 |
| 25 | 11.9 | 6:13 | 6:07 |
| 26 | 11.9 | 6:14 | 6:05 |
| 27 | 11.8 | 6:15 | 6:04 |
| 28 | 11.8 | 6:15 | 6:03 |
| 29 | 11.7 | 6:16 | 6:01 |
| 30 | 11.7 | 6:17 | 6:00 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 4.32 kWh/m².
For context, solar energy here swings from a low near 2.2 kWh/m² to a high of 5.28 kWh/m² in May across the year — September's 4.32 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) | 4.7 | 4.6 | 4.6 | 4.6 | 4.6 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.5 | 4.4 | 4.4 | 4.4 | 4.4 | 4.3 | 4.3 | 4.3 | 4.3 | 4.3 | 4.2 | 4.2 | 4.2 | 4.2 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.0 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.7 | Bright |
| 2 | 4.6 | Bright |
| 3 | 4.6 | Bright |
| 4 | 4.6 | Bright |
| 5 | 4.6 | Bright |
| 6 | 4.5 | Bright |
| 7 | 4.5 | Bright |
| 8 | 4.5 | Bright |
| 9 | 4.5 | Bright |
| 10 | 4.5 | Bright |
| 11 | 4.5 | Bright |
| 12 | 4.4 | Bright |
| 13 | 4.4 | Bright |
| 14 | 4.4 | Bright |
| 15 | 4.4 | Bright |
| 16 | 4.3 | Bright |
| 17 | 4.3 | Bright |
| 18 | 4.3 | Bright |
| 19 | 4.3 | Bright |
| 20 | 4.3 | Bright |
| 21 | 4.2 | Bright |
| 22 | 4.2 | Bright |
| 23 | 4.2 | Bright |
| 24 | 4.2 | Bright |
| 25 | 4.1 | Bright |
| 26 | 4.1 | Bright |
| 27 | 4.1 | Bright |
| 28 | 4.1 | Bright |
| 29 | 4.1 | Bright |
| 30 | 4.0 | Bright |
Hazard calendar for Unzen
In September, Unzen sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Unzen sits in the Pacific typhoon belt; the season peaks July–October.
Unzen's rainy season runs June–July, when most of the year's rain falls.
Is September a good time to visit Unzen?
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 Unzen for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Unzen in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Unzen sees daytime highs around 29°C and nights near 22°C. Pack light clothes. Worth having: rain gear. About 12 days see rain.
Sea temperature near Unzen in September
The nearest coast averages about 26°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 17 km away) is warmest in August at about 27°C and coldest in February near 14°C.
It's comfortable for a long swim from May 27 to Nov 14 — about 5.7 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 15 | 14 | 14 | 16 | 19 | 22 | 25 | 27 | 26 | 23 | 20 | 17 |
| Comfort | Bracing | Bracing | Bracing | Cool | Cool | Refreshing | Warm | Warm | Warm | Refreshing | Cool | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 15 | Bracing |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 16 | Cool |
| May | 19 | Cool |
| Jun | 22 | Refreshing |
| Jul | 25 | Warm |
| Aug | 27 | Warm |
| Sep | 26 | Warm |
| Oct | 23 | Refreshing |
| Nov | 20 | Cool |
| Dec | 17 | Cool |
UV index in Unzen in September
Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Unzen peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 3 | 4 | 6 | 8 | 8 | 10 | 10 | 9 | 10 | 7 | 4 | 3 |
| 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 | 8 | Very high |
| May | 8 | Very high |
| Jun | 10 | Very high |
| Jul | 10 | Extreme |
| Aug | 9 | Very high |
| Sep | 10 | Very high |
| Oct | 7 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Air quality in Unzen 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 Unzen is worst in March — around 25 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (July, 13 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) | 18 | 20 | 25 | 25 | 23 | 19 | 13 | 15 | 14 | 14 | 16 | 15 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 18 | Moderate |
| Feb | 20 | Moderate |
| Mar | 25 | Moderate |
| Apr | 25 | Moderate |
| May | 23 | Moderate |
| Jun | 19 | Moderate |
| Jul | 13 | Moderate |
| Aug | 15 | Moderate |
| Sep | 14 | Moderate |
| Oct | 14 | Moderate |
| Nov | 16 | Moderate |
| Dec | 15 | Moderate |
Where is Unzen?
Unzen sits at 32.8°N, 130.2°E, 546 m above sea level, in Japan. The nearest listed city is Minamishimabara, 11 km away.
Topography around Unzen
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Unzen.
Within 3 km, the terrain around Unzen has large variations in elevation — a maximum elevation change of 954 m around an average of 559 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,450 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,724 m.
The land around Unzen is covered by trees (96%) within 3 km, water (42%) and trees (37%) within 16 km, and trees (46%) and water (39%) 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 Unzen (32.7711°, 130.2484°, elevation 546 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).