Climate averages 1991–2020
Ansan-si weather
in September.
A warm, wet month: the 4th warmest and the joint 9th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Ansan-si: daytime highs average 24.3°C and nights cool to about 17.8°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 127 mm of rain on roughly 7 days, which makes September a wet month (the joint 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 28 min on an average September day.
The nearest other city in this atlas is Anyang-si (12 km away). In September its highs average 24.3°C, about as warm as Ansan-si, with 124 mm of rain.
Among the 79 cities listed in South Korea, Ansan-si ranks joint 64th of 79 for the warmest September highs and joint 14th of 79 for the driest September (rainfall, lowest first). The mean September high of those 79 cities is 24.8°C; Ansan-si is 0.4°C cooler than that mean.
From September to October, average highs fall by 5.9°C to 18.5°C, and monthly rainfall falls from 127 mm to 62 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Ansan-si climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.9°C-4.9°C | -4.9°C | 22 | 4.1 | 9.910 h |
| February | 4.3°C-3.3°C | -3.3°C | 30 | 4.3 | 10.811 h |
| March | 9.2°C0.7°C | 0.7°C | 42 | 6.1 | 11.912 h |
| April | 15.3°C6.2°C | 6.2°C | 79 | 7.3 | 13.113 h |
| May | 20.5°C11.9°C | 11.9°C | 104 | 7.7 | 14.214 h |
| June | 24.8°C17.2°C | 17.2°C | 127 | 7.6 | 14.715 h |
| July | 27.1°C21.6°C | 21.6°C | 298 | 14.4 | 14.514 h |
| August | 28.0°C22.6°C | 22.6°C | 239 | 12.8 | 13.614 h |
| September, selected | 24.3°C17.8°C | 17.8°C | 127 | 7.3 | 12.512 h |
| October | 18.5°C10.9°C | 10.9°C | 62 | 5.6 | 11.311 h |
| November | 11.1°C3.7°C | 3.7°C | 57 | 8.2 | 10.210 h |
| December | 4.1°C-2.7°C | -2.7°C | 28 | 5.8 | 9.610 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Anyang-si in SeptemberSouth Korea · 12 kmHigh 24.3°C · Low 17.3°C · 124 mm rain
- Hwaseong-si in SeptemberSouth Korea · 13 kmHigh 23.9°C · Low 18.4°C · 127 mm rain
- Suwon in SeptemberSouth Korea · 17 kmHigh 24.5°C · Low 16.7°C · 124 mm rain
- Gwangmyeong in SeptemberSouth Korea · 18 kmHigh 24.6°C · Low 17.0°C · 121 mm rain
- Incheon in SeptemberSouth Korea · 18 kmHigh 24.0°C · Low 17.7°C · 121 mm rain
- Bucheon-si in SeptemberSouth Korea · 20 kmHigh 24.4°C · Low 17.4°C · 121 mm rain
- Osan in SeptemberSouth Korea · 29 kmHigh 24.8°C · Low 16.9°C · 124 mm rain
- Seoul in SeptemberSouth Korea · 30 kmHigh 24.7°C · Low 16.4°C · 124 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Ansan-si) is explained once on the Ansan-si year overview and on the Sources, method and limits page.
Hwaseong-si lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.