Climate & Weather in Iwakuni

Post date: Tuesday, August 1, 2017

For foreign expats moving to Iwakuni City from overseas countries as well as ones moving to the city from other areas in Japan, we here provide the guidance on Iwakuni weather. We will be happy if it could help you to prepare for your seasonal clothing and more for your life in Japan.

Iwakuni City, like most of the rest of the world, has a fair amount of seasonal variation in its weather patterns. For the most part, the weather is fairly mild and generally quite pleasant though there is a typhoon (also known as a hurricane or tropical cyclone) season that runs from May to December when the weather can get very bad, very quickly if a storm is passing by.

Rainfall Level & Average Temperature in Iwakuni (2019)

The below is the Rainfall Level and Average Temperature in Iwakuni City. Rainfall is more frequent from March through October, during which includes Rainy Season in June-July and Typhoon peak season in September in the city. However, the city lies between Chugoku Mountains and Shikoku Mountains and is seldom affected by rain and snow, resulting in a city with one of the least rainy days per year in Japan and many fine days all year round. Iwakuni weather is also mild throughout four seasons thanks to the warm seawater of Seto Inland Sea and having less influence of rainy season and typhoon.

  Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept. Oct. Nov. Dec.
Rainfall Level (mm) 22.5 96 148.5 177.5 54.5 185 371.5 217 70 105.5 12 121.5
Max.Temp ( °C) 10.9 11 15.1 19.1 25.6 27.2 29.4 31.6 29.9 24.2 18 12.8
Ave.Temp ( °C) 5.6 6.4 9.6 13.7 19 22.1 25.3 27.2 24.9 19.1 12.1 7.7
Min.Temp ( °C) 0.9 2.1 4.5 8.6 12.9 17.7 22.4 23.8 20.9 14.6 7.1 3.5

Average Temperature & Humidity in Iwakuni (2019)

  Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept. Oct. Nov. Dec.
Ave.Temp ( °C) 5.6 6.4 9.6 13.7 19 22.1 25.3 27.2 24.9 19.1 12.1 7.7
Ave.Temp ( °F) 42.08 43.52 49.28 56.66 66.2 71.78 77.54 80.96 76.82 66.38 53.78 45.86
Humidity (%) 60 58 58 55 49 63 72 68 63 63 60 65

It has been really unlike the average data for these past several years that the days of intense heat and the highest temperature more than 35 degree continue in summer due to global warming and heat island effects, and so we cannot spend a day without air conditioner.

Seasonal Clothing (for Iwakuni & Vincinity)

  • Spring (Mar. - May): Topcoat, jacket, sweater
  • Summer (Jun. - Aug.): Light clothing, short sleeves
  • Autumn (Sep. - Nov.): same as Spring
  • Winter (Dec. - Feb.): Down jacket, wool coat, warm sweater, scarf, gloves

The best times to visit are April-May, for the well-known blooming of cherry blossoms with pleasant climate, and October-November for autumn leaves changing and enjoyable climate. It can get hot and extremely muggy in July-August. Winter seldom brings snow and only a few days per year the temperatures drop below freezing. It is also helpful for you to see Seasonal Clothing idea above.

The Weather in Iwakuni and Advice for Every Season

Iwakuni is an urbanized city and most people get around using public transit, bikes, or their feet. Here are a few tips & tricks to make surviving close encounters with Mother Nature a little easier:

■ Precipitation

Always check the forecast before you leave for the day and pack an umbrella if rain is predicted.

It’s no fun being caught in a downpour and waiting under the corner of a ramen shop’s roof waiting for the rain to pass.

o Pro tip: If weather forecasts aren’t to your liking, stick your head outside before you leave for the day and see if others are carrying umbrellas and follow their lead. If you do get stuck in the wet, you can always duck into the nearest convenience store for a cheap umbrella—they’re everywhere!

■ Heat

It can get quite hot in Iwakuni so dress accordingly. Iwakuni is a concrete jungle that displays the "heat island" effect common in big cities.

o Pro tip: If you’re going to work, check and see if your office follows a "cool biz" dress code which is a set of comparatively relaxed dress guidelines encouraged by the Japanese government to help make life more comfortable for office-workers in the summer.