Mud festival in South Korea
In July, the peaceful seaside town of Boryeong turned into a chaos of mud for 9 days. We recommend putting this festival on your bucket list.
Ansan Weather in September
September in Ansan typically sees daytime highs of 26°C (79°F) and nighttime lows of 19°C (66°F). Rainfall is also possible this month, so it's worth packing an umbrella. It falls within the summer season.
Rainfall in Ansan in September
Looking at the last 30 years, the data shows about 8 days with rain, averaging 132 mm (5.2 in) for the month. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.
Temperature in Ansan in September
Ansan in September gets highs of 26°C (79°F) during the day and drops to 19°C (66°F) at night. September is in the summer season. This kind of day-to-night contrast is typical for this time of year. With lows of 19°C (66°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.
Sunshine in Ansan in September
The city usually sees around 202 hours of sunlight, indicating many sunny days , a great month for sightseeing.Our weather planner can help you find worldwide destinations with pleasant weather during this period. October typically offers the best weather for Ansan.
Ansan Temperature in September
Min Temperature
19°C (66°F)
Max Temperature
26°C (79°F)
Chance of Rain
28%
Precipitation
132 mm (5.2 in)
Rainy days
8 days
Humidity
71% *
Sunshine
202 hours *
Percentage Sunshine
*
* Data from: Incheon, South Korea (18 KM, 11 Miles).
Ansan Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Ansan - and find the best time to visit.
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Ansan typically drop from around 28°C (82°F) at the start of September to approximately 24°C (75°F) by the end. Nights are pleasant, with lows typically ranging from 13°C (55°F) to 20°C (68°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather records for Ansan in September
Browse day-by-day weather records for Ansan spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Ansan historical weather extremes in September
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Ansan.
- Ansan recorded its highest September temperature of 34°C (93°F) on September 11, 2024.
- On September 26, 1987, Ansan saw its coldest September day with temperatures maxing out at 16°C (61°F).
- The coldest night in September in Ansan was on September 27, 1987, with a minimum of 4°C (39°F).
Best Places in South Korea in September
Find out more about the weather in South Korea and which places have the best travel conditions in this month. See all of South Korea in September →
perfect weather
pleasant
tolerable
unpleasant
poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).
What to Wear in Ansan in September
Warm but pleasant conditions in Ansan in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Expect heavy rainfall, so bring good rain protection and waterproof bags. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.
What To Do in Ansan in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
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Swimming9/10 -
Cycling7/10 -
Walking7/10 -
Camping6/10 -
Outdoor sports7/10
Ansan 3-Day Forecast
More climate data for Ansan
Temperature Rainfall Sunshine Humidity
See the full Ansan climate overview or explore weather in South Korea.
Popular in September
Where to go in September - average daytime high across popular destinations.
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Mud festival in South Korea
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