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.
Osan Travel Guide
Other Osan Travel Info
Weather in Osan
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)
Osan Temperatures (Celsius)
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)
Osan Perceived Temperature (C)
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.
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
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.
Snow on the Ground
The graph below shows the average snow on the ground in Osan (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
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.
The graph below shows wind speed (max and average) in knots.
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|
Is it Safe to Travel to Osan?
Our best data indicates this area is generally safe. As of Oct 07, 2019 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 03, 2019.
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
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.