Ulsan weather in September
In September, Ulsan sees average daytime highs of 25°C and overnight lows near 19°C, with 173 mm of rain across 10.4 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 27°C in the first days to 24°C by the end. The sky is clear or mostly clear about 26% 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 Ulsan's 9th-clearest and 5th-windiest month. For the whole year in context, see Ulsan's year-round climate.
- Daytime high
- 25°
- 3rd warmest
- Overnight low
- 19°
- 10th coldest
- Rainfall
- 173 mm
- 10.4 wet days
- Daylight
- 12 h 12 min
- 6:10 AM – 6:24 PM
- Cloud cover
- 63%
- 9th clearest
- Wind
- 12 km/h
- 5th windiest
- Solar energy
- 4.13 kWh/m²
- Travel score
- 6.6
- out of 10
- Air quality
- Elevated
- PM2.5 17 µg/m³ · 2020
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in September
Highs ease over the month, from about 27°C in the first days to 24°C by the end.
A typical September day in Ulsan reaches about 25°C in the afternoon and slips back to 19°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 29°C. Set against its neighbours, September runs about 4°C cooler than August and about 4°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) | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 26 | 26 | 26 | 26 | 26 | 26 | 26 | 25 | 25 | 25 | 25 | 25 | 25 | 25 | 24 | 24 | 24 | 24 | 24 | 24 | 24 | 23 |
| Avg low (°C) | 22 | 22 | 21 | 21 | 21 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 | 20 | 19 | 19 | 19 | 19 | 19 | 18 | 18 | 18 | 18 | 18 | 17 | 17 | 17 | 17 | 17 | 16 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| 1 | 27 | 22 |
| 2 | 27 | 22 |
| 3 | 27 | 21 |
| 4 | 27 | 21 |
| 5 | 27 | 21 |
| 6 | 27 | 21 |
| 7 | 27 | 21 |
| 8 | 27 | 21 |
| 9 | 26 | 20 |
| 10 | 26 | 20 |
| 11 | 26 | 20 |
| 12 | 26 | 20 |
| 13 | 26 | 20 |
| 14 | 26 | 20 |
| 15 | 26 | 19 |
| 16 | 25 | 19 |
| 17 | 25 | 19 |
| 18 | 25 | 19 |
| 19 | 25 | 19 |
| 20 | 25 | 18 |
| 21 | 25 | 18 |
| 22 | 25 | 18 |
| 23 | 24 | 18 |
| 24 | 24 | 18 |
| 25 | 24 | 17 |
| 26 | 24 | 17 |
| 27 | 24 | 17 |
| 28 | 24 | 17 |
| 29 | 24 | 17 |
| 30 | 23 | 16 |
How September really feels in Ulsan
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.
Ulsan 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 | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 7° / -1° | 31 | 4.4 | 0.7 | 9.9 | 1.0 |
| Feb | 9° / 0° | 39 | 5 | 0.9 | 10.7 | 2.0 |
| Mar | 13° / 4° | 71 | 7.4 | 0.5 | 11.7 | 4.0 |
| Apr | 18° / 8° | 92 | 7.6 | 0 | 12.9 | 6.3 |
| May | 23° / 13° | 100 | 7.8 | 0 | 13.8 | 7.1 |
| Jun | 25° / 18° | 143 | 9.1 | 0 | 14.4 | 6.7 |
| Jul | 28° / 23° | 216 | 13.3 | 0 | 14.2 | 5.3 |
| Aug | 29° / 23° | 213 | 14.2 | 0 | 13.3 | 4.9 |
| Sep | 25° / 19° | 173 | 10.4 | 0 | 12.2 | 6.6 |
| Oct | 21° / 13° | 73 | 5.1 | 0 | 11.1 | 7.4 |
| Nov | 15° / 6° | 48 | 4.9 | 0.1 | 10.1 | 5.4 |
| Dec | 9° / 1° | 27 | 3.6 | 0.3 | 9.6 | 2.2 |
Cloud cover in September
The sky is clear or mostly clear about 26% of the time in September.
Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 57%. 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 (%) | 37 | 37 | 37 | 37 | 37 | 38 | 38 | 39 | 40 | 41 | 41 | 41 | 42 | 42 | 43 | 44 | 45 | 45 | 45 | 45 | 47 | 47 | 47 | 47 | 47 | 47 | 47 | 48 | 48 | 48 |
| Cloudier (%) | 63 | 63 | 63 | 63 | 63 | 62 | 62 | 61 | 60 | 59 | 59 | 59 | 58 | 58 | 57 | 56 | 55 | 55 | 55 | 55 | 53 | 53 | 53 | 53 | 53 | 53 | 53 | 52 | 52 | 52 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 37 | 63 |
| 2 | 37 | 63 |
| 3 | 37 | 63 |
| 4 | 37 | 63 |
| 5 | 37 | 63 |
| 6 | 38 | 62 |
| 7 | 38 | 62 |
| 8 | 39 | 61 |
| 9 | 40 | 60 |
| 10 | 41 | 59 |
| 11 | 41 | 59 |
| 12 | 41 | 59 |
| 13 | 42 | 58 |
| 14 | 42 | 58 |
| 15 | 43 | 57 |
| 16 | 44 | 56 |
| 17 | 45 | 55 |
| 18 | 45 | 55 |
| 19 | 45 | 55 |
| 20 | 45 | 55 |
| 21 | 47 | 53 |
| 22 | 47 | 53 |
| 23 | 47 | 53 |
| 24 | 47 | 53 |
| 25 | 47 | 53 |
| 26 | 47 | 53 |
| 27 | 47 | 53 |
| 28 | 48 | 52 |
| 29 | 48 | 52 |
| 30 | 48 | 52 |
Chance of precipitation in September
Ulsan gets around 173 mm of rain over 10.4 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 35% and peaks near 43% 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 (%) | 43 | 43 | 43 | 43 | 42 | 42 | 42 | 41 | 41 | 40 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 | 31 | 30 | 29 | 28 | 28 | 27 | 26 | 25 | 25 | 24 | 23 |
| Rain chance (%) | |
|---|---|
| 1 | 43 |
| 2 | 43 |
| 3 | 43 |
| 4 | 43 |
| 5 | 42 |
| 6 | 42 |
| 7 | 42 |
| 8 | 41 |
| 9 | 41 |
| 10 | 40 |
| 11 | 40 |
| 12 | 39 |
| 13 | 38 |
| 14 | 37 |
| 15 | 36 |
| 16 | 35 |
| 17 | 34 |
| 18 | 33 |
| 19 | 32 |
| 20 | 31 |
| 21 | 30 |
| 22 | 29 |
| 23 | 28 |
| 24 | 28 |
| 25 | 27 |
| 26 | 26 |
| 27 | 25 |
| 28 | 25 |
| 29 | 24 |
| 30 | 23 |
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 28% of days. Sticky, muggy-or-worse air turns up on roughly 44% 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 | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | 4 | 5 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 13 | 14 | 15 | 17 | 19 | 21 | 23 | 25 | 27 | 30 |
| Comfortable (%) | 4 | 4 | 4 | 5 | 6 | 6 | 7 | 8 | 9 | 11 | 12 | 13 | 15 | 17 | 18 | 20 | 21 | 23 | 25 | 26 | 27 | 29 | 30 | 30 | 31 | 31 | 32 | 32 | 31 | 31 |
| Humid (%) | 19 | 20 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 29 | 30 | 30 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 31 | 30 | 30 | 29 | 29 | 28 | 27 | 26 | 25 |
| Muggy (%) | 37 | 38 | 39 | 39 | 39 | 39 | 39 | 39 | 38 | 38 | 37 | 35 | 34 | 32 | 31 | 29 | 28 | 26 | 25 | 23 | 22 | 20 | 19 | 17 | 16 | 15 | 14 | 13 | 12 | 11 |
| Oppressive (%) | 33 | 32 | 30 | 28 | 27 | 25 | 24 | 22 | 21 | 19 | 18 | 17 | 16 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 6 | 5 | 5 | 4 | 4 | 3 | 3 | 3 |
| Miserable (%) | 6 | 6 | 5 | 4 | 4 | 3 | 3 | 2 | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 4 | 19 | 37 | 33 | 6 |
| 2 | 0 | 4 | 20 | 38 | 32 | 6 |
| 3 | 0 | 4 | 22 | 39 | 30 | 5 |
| 4 | 1 | 5 | 23 | 39 | 28 | 4 |
| 5 | 1 | 6 | 24 | 39 | 27 | 4 |
| 6 | 1 | 6 | 25 | 39 | 25 | 3 |
| 7 | 1 | 7 | 26 | 39 | 24 | 3 |
| 8 | 2 | 8 | 27 | 39 | 22 | 2 |
| 9 | 2 | 9 | 28 | 38 | 21 | 2 |
| 10 | 3 | 11 | 29 | 38 | 19 | 1 |
| 11 | 3 | 12 | 29 | 37 | 18 | 1 |
| 12 | 4 | 13 | 30 | 35 | 17 | 1 |
| 13 | 5 | 15 | 30 | 34 | 16 | 1 |
| 14 | 5 | 17 | 31 | 32 | 14 | 0 |
| 15 | 6 | 18 | 31 | 31 | 13 | 0 |
| 16 | 7 | 20 | 31 | 29 | 12 | 0 |
| 17 | 8 | 21 | 31 | 28 | 11 | 0 |
| 18 | 9 | 23 | 31 | 26 | 10 | 0 |
| 19 | 10 | 25 | 31 | 25 | 9 | 0 |
| 20 | 11 | 26 | 31 | 23 | 8 | 0 |
| 21 | 13 | 27 | 31 | 22 | 7 | 0 |
| 22 | 14 | 29 | 31 | 20 | 6 | 0 |
| 23 | 15 | 30 | 30 | 19 | 6 | 0 |
| 24 | 17 | 30 | 30 | 17 | 5 | 0 |
| 25 | 19 | 31 | 29 | 16 | 5 | 0 |
| 26 | 21 | 31 | 29 | 15 | 4 | 0 |
| 27 | 23 | 32 | 28 | 14 | 4 | 0 |
| 28 | 25 | 32 | 27 | 13 | 3 | 0 |
| 29 | 27 | 31 | 26 | 12 | 3 | 0 |
| 30 | 30 | 31 | 25 | 11 | 3 | 0 |
Wind in September
Winds average 12 km/h in September.
Across September, daily wind ranges from about 11 km/h on the calmest days to 12 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) | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 12 | 11 | 11 | 11 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | light breeze | light breeze | light breeze | light breeze | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| 1 | 12 | calm |
| 2 | 12 | calm |
| 3 | 12 | calm |
| 4 | 12 | calm |
| 5 | 12 | calm |
| 6 | 12 | calm |
| 7 | 12 | calm |
| 8 | 12 | calm |
| 9 | 12 | calm |
| 10 | 12 | calm |
| 11 | 12 | calm |
| 12 | 12 | calm |
| 13 | 12 | calm |
| 14 | 12 | calm |
| 15 | 12 | calm |
| 16 | 12 | light breeze |
| 17 | 12 | light breeze |
| 18 | 12 | light breeze |
| 19 | 12 | light breeze |
| 20 | 12 | calm |
| 21 | 12 | calm |
| 22 | 12 | calm |
| 23 | 12 | calm |
| 24 | 12 | calm |
| 25 | 12 | calm |
| 26 | 12 | calm |
| 27 | 12 | calm |
| 28 | 11 | calm |
| 29 | 11 | calm |
| 30 | 11 | 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 5:59 AM to 6:22 AM, and sunset from 6:46 PM to 6:03 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 | 12.4 | 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) | 5:59 | 6:00 | 6:00 | 6:01 | 6:02 | 6:03 | 6:03 | 6:04 | 6:05 | 6:06 | 6:07 | 6:07 | 6:08 | 6:09 | 6:10 | 6:10 | 6:11 | 6:12 | 6:13 | 6:14 | 6:14 | 6:15 | 6:16 | 6:17 | 6:18 | 6:18 | 6:19 | 6:20 | 6:21 | 6:22 |
| Sunset (PM) | 6:46 | 6:45 | 6:43 | 6:42 | 6:40 | 6:39 | 6:37 | 6:36 | 6:34 | 6:33 | 6:31 | 6:30 | 6:28 | 6:27 | 6:25 | 6:24 | 6:22 | 6:21 | 6:19 | 6:18 | 6:16 | 6:15 | 6:13 | 6:12 | 6:10 | 6:09 | 6:07 | 6:06 | 6:04 | 6:03 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 12.8 | 5:59 | 6:46 |
| 2 | 12.8 | 6:00 | 6:45 |
| 3 | 12.7 | 6:00 | 6:43 |
| 4 | 12.7 | 6:01 | 6:42 |
| 5 | 12.6 | 6:02 | 6:40 |
| 6 | 12.6 | 6:03 | 6:39 |
| 7 | 12.6 | 6:03 | 6:37 |
| 8 | 12.5 | 6:04 | 6:36 |
| 9 | 12.5 | 6:05 | 6:34 |
| 10 | 12.4 | 6:06 | 6:33 |
| 11 | 12.4 | 6:07 | 6:31 |
| 12 | 12.4 | 6:07 | 6:30 |
| 13 | 12.3 | 6:08 | 6:28 |
| 14 | 12.3 | 6:09 | 6:27 |
| 15 | 12.3 | 6:10 | 6:25 |
| 16 | 12.2 | 6:10 | 6:24 |
| 17 | 12.2 | 6:11 | 6:22 |
| 18 | 12.1 | 6:12 | 6:21 |
| 19 | 12.1 | 6:13 | 6:19 |
| 20 | 12.1 | 6:14 | 6:18 |
| 21 | 12.0 | 6:14 | 6:16 |
| 22 | 12.0 | 6:15 | 6:15 |
| 23 | 12.0 | 6:16 | 6:13 |
| 24 | 11.9 | 6:17 | 6:12 |
| 25 | 11.9 | 6:18 | 6:10 |
| 26 | 11.8 | 6:18 | 6:09 |
| 27 | 11.8 | 6:19 | 6:07 |
| 28 | 11.8 | 6:20 | 6:06 |
| 29 | 11.7 | 6:21 | 6:04 |
| 30 | 11.7 | 6:22 | 6:03 |
Solar energy in September
Average shortwave solar energy reaching the ground each day in September, about 4.13 kWh/m².
For context, solar energy here swings from a low near 2.65 kWh/m² to a high of 5.9 kWh/m² in May across the year — September's 4.13 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) | 4.4 | 4.4 | 4.3 | 4.3 | 4.3 | 4.3 | 4.3 | 4.2 | 4.2 | 4.2 | 4.2 | 4.2 | 4.2 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 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 | Moderate | Moderate |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 4.4 | Bright |
| 2 | 4.4 | Bright |
| 3 | 4.3 | Bright |
| 4 | 4.3 | Bright |
| 5 | 4.3 | Bright |
| 6 | 4.3 | Bright |
| 7 | 4.3 | Bright |
| 8 | 4.2 | Bright |
| 9 | 4.2 | Bright |
| 10 | 4.2 | Bright |
| 11 | 4.2 | Bright |
| 12 | 4.2 | Bright |
| 13 | 4.2 | Bright |
| 14 | 4.1 | Bright |
| 15 | 4.1 | Bright |
| 16 | 4.1 | Bright |
| 17 | 4.1 | Bright |
| 18 | 4.1 | Bright |
| 19 | 4.1 | Bright |
| 20 | 4.1 | Bright |
| 21 | 4.1 | Bright |
| 22 | 4.1 | Bright |
| 23 | 4.0 | Bright |
| 24 | 4.0 | Bright |
| 25 | 4.0 | Bright |
| 26 | 4.0 | Bright |
| 27 | 4.0 | Bright |
| 28 | 4.0 | Bright |
| 29 | 4.0 | Moderate |
| 30 | 4.0 | Moderate |
Hazard calendar for Ulsan
In September, Ulsan sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.
Ulsan sits in the Pacific typhoon belt; the season peaks July–October.
Ulsan's rainy season runs May–September, when most of the year's rain falls.
Is September a good time to visit Ulsan?
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 Ulsan for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Ulsan in September
From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In September, Ulsan sees daytime highs around 25°C and nights near 19°C. Worth packing: light clothes and rain gear. About 10 days see rain.
Sea temperature near Ulsan 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 19 km away) is warmest in August at about 26°C and coldest in February near 14°C.
It's comfortable for a long swim from Jun 17 to Nov 9 — about 4.8 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 | 15 | 17 | 20 | 23 | 26 | 25 | 22 | 20 | 17 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Refreshing | Warm | Warm | Refreshing | Cool | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 15 | Bracing |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 15 | Bracing |
| May | 17 | Cool |
| Jun | 20 | Refreshing |
| Jul | 23 | Refreshing |
| Aug | 26 | Warm |
| Sep | 25 | Warm |
| Oct | 22 | Refreshing |
| Nov | 20 | Cool |
| Dec | 17 | Cool |
UV index in Ulsan 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 Ulsan peaks around August 17 at about 9 (very high) — 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) | 2 | 4 | 5 | 7 | 8 | 8 | 9 | 9 | 9 | 5 | 4 | 2 |
| Level | Moderate | Moderate | High | High | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | High |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 8 | Very high |
| Jul | 9 | Very high |
| Aug | 9 | Very high |
| Sep | 9 | Very high |
| Oct | 5 | High |
| Nov | 4 | Moderate |
| Dec | 2 | Moderate |
Air quality in Ulsan 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 Ulsan is worst in March — around 21 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (August, 13 µg/m³).
Seasonal pattern from CAMS reanalysis, scaled to Ulsan's WHO annual average of 17 µg/m³.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 16 | 18 | 21 | 21 | 20 | 17 | 14 | 13 | 14 | 16 | 18 | 15 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 16 | Moderate |
| Feb | 18 | Moderate |
| Mar | 21 | Moderate |
| Apr | 21 | Moderate |
| May | 20 | Moderate |
| Jun | 17 | Moderate |
| Jul | 14 | Moderate |
| Aug | 13 | Moderate |
| Sep | 14 | Moderate |
| Oct | 16 | Moderate |
| Nov | 18 | Moderate |
| Dec | 15 | Moderate |
Where is Ulsan?
Ulsan sits at 35.5°N, 129.3°E, 10 m above sea level, in South Korea. The nearest listed city is Ungsang, 20 km away.
Topography around Ulsan
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ulsan.
Within 3 km, the terrain around Ulsan has only modest variations in elevation — a maximum elevation change of 136 m around an average of 26 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 752 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,204 m.
The land around Ulsan is covered by artificial surfaces (61%) and trees (30%) within 3 km, trees (55%) within 16 km, and trees (44%) and water (40%) within 80 km.
South Korea travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / F
- 220 V · 60 Hz
- Prices
- ≈ 57% of US
- price level, 2025
- GDP per capita
- $36,227
- 2025
- Happiness
- 6.0 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.5
- per 100k, 2023
- Road deaths
- 8.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 522
- 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 Ulsan (35.5372°, 129.3167°, elevation 10 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).