The best times to visit Osan for ideal weather are

April 30th to June 24th

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.

 

 


Other Osan Travel Info

Weather in Osan

Temperature

Average temperatures in Osan vary an incredible amount. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a fair chance of precipitation about half of the year. The area is less temperate than some — in the 30th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Osan, the hottest months are August, July, and then June. See average monthly temperatures below. The warmest time of year is generally early August where highs are regularly around 89°F (31.7°C) with temperatures rarely dropping below 73.2°F (22.9°C) at night.

Osan Temperatures (Fahrenheit)

Key
High
Average
Low

Osan Temperatures (Celsius)

Key
High
Average
Low

“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

Osan Perceived Temperature (F)

Key
High
Average
Low

Osan Perceived Temperature (C)

Key
High
Average
Low

 

Average Osan Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 36.1 25.9 14
Feb 42.6 32.1 20.3
Mar 52 41.1 28.6
Apr 63.7 51.9 38.5
May 75 63.6 51.1
Jun 82.2 72.3 62.4
Jul 84.8 77.3 70.5
Aug 86.3 78.2 70.9
Sep 79.3 69.3 59.8
Oct 69.5 57 44.9
Nov 54.4 44.1 33.2
Dec 39.4 30.1 19

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 2.3 -3.4 -10
Feb 5.9 0.1 -6.5
Mar 11.1 5.1 -1.9
Apr 17.6 11.1 3.6
May 23.9 17.6 10.6
Jun 27.9 22.4 16.9
Jul 29.3 25.2 21.4
Aug 30.2 25.7 21.6
Sep 26.3 20.7 15.4
Oct 20.8 13.9 7.2
Nov 12.4 6.7 0.7
Dec 4.1 -1.1 -7.2

 


 

Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Osan are January, February, and then October. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early January. For example, on the week of January 1st there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in early to mid July with an average of 3 days of significant precipitation the week of July 9th.

When can you find snow in Osan? Weather stations report a good amount of seasonal snow likely to be deepest around January, especially close to early to mid March. The best time to ski (if at all) in Osan is often around around January 22nd when fresh powder is deepest. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in Osan.

Key
Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Osan (in).

Key
Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 4% 3.2 0.5
Feb 9% 1.7 1.1
Mar 14% 2.3 2
Apr 18% 0 2.5
May 13% 0 3.6
Jun 18% 0 4.4
Jul 39% 0 15
Aug 31% 0 10
Sep 19% 0 5.4
Oct 10% 0 1.4
Nov 16% 0 1.7
Dec 10% 1.7 1.1

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 4 8.1 1.3
Feb 9 4.3 2.8
Mar 14 5.8 5.1
Apr 18 0 6.4
May 13 0 9.1
Jun 18 0 11.2
Jul 39 0 38.1
Aug 31 0 25.4
Sep 19 0 13.7
Oct 10 0 3.6
Nov 16 0 4.3
Dec 10 4.3 2.8

 

Humidity and Wind

Osan has some extremely humid months, and above average humidity throughout the year. The least humid month is March (60% relative humidity), and the most humid month is July (83.7%).

Wind in Osan is usually calm. The windiest month is April, followed by March and May. April’s average wind speed of around 5.8 knots (6.7 MPH or 10.8 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early April where average top sustained speeds reach 14 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Osan.

Key
Avg. Relative Humidity

Wind

The graph below shows wind speed (max and average) in knots.

Key
Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 4.1 Light breeze 10 Gentle breeze
Feb 4.5 Light breeze 10.7 Gentle breeze
Mar 5.7 Light breeze 12.9 Gentle breeze
Apr 5.8 Light breeze 13.5 Significant breeze
May 5.2 Light breeze 11.8 Gentle breeze
Jun 4.5 Light breeze 10.4 Gentle breeze
Jul 4.8 Light breeze 10.8 Gentle breeze
Aug 4.6 Light breeze 10.6 Gentle breeze
Sep 4 Light breeze 9 Gentle breeze
Oct 4.1 Light breeze 9.6 Gentle breeze
Nov 4.4 Light breeze 10.7 Gentle breeze
Dec 4.4 Light breeze 10.5 Gentle breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 65.8%
Feb 61.2%
Mar 60%
Apr 60.8%
May 65.4%
Jun 70.7%
Jul 83.7%
Aug 82.6%
Sep 75.5%
Oct 70.5%
Nov 69.1%
Dec 66.6%

 

Is it Safe to Travel to Osan?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for South Korea; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Oct 30, 2023.


 

The Busiest and Least Crowded Months

The busiest month for tourism in Osan, South Korea is April, followed by March and September. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Osan in July. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month

 

Most Popular Months to Visit

Key
Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is slightly extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 56.7 in July means 56.7% of the tourists vs. April.

 

 

Overall Osan Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderately cold. Highs range from 79°F (26.1°C) and 47.5°F (8.6°C) with far warmer temperatures in the later months. Rain is somewhat common with 4 to 5 days of significant precipitation per month. Spring is the busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are comfortable. These months see the most precipitation with 5 to 12 days of precipitation per month. June – August is the slowest season for tourism in Osan, so lodging and other accommodations may cost less than usual.

Fall (September through November)

Fall daily highs range from 81.2°F (27.3°C) and 48.2°F (9°C), which will feel comfortable given the humidity and wind. It rains or snows a significant amount: 3 to 6 days per month. Tourism is fairly slow during these months due to the weather, so hotels may be lower priced.

Winter (December through February)

Weather is far too cold this time of year in Osan to be enjoyable for warm weather travelers. The average high during this season is between 48.2°F (9°C) and 34°F (1.1°C). On average, it rains or snows a smalll amount: 1 to 3 times per month. These times of year are the second busiest with tourists.

 

Best Times to Travel› South Korea › Osan, South Korea