Izu Peninsula Weather

 What is the weather like in Izu? Having a temperate marine climate, Izu Peninsula enjoys four diverse seasons: mild springs from March to May, muggy summers from June to August, cool autumns from September to November and chilly winters from December to February. Under the influence of the Kuroshio Current, the weather is quite changeable. Rainfall mainly comes from summer and autumn, and the rainy season lasts from early June to mid-July. Except for high-elevation regions, the peninsula seldom sees snow.

Temperature

Thanks to its oceanic influence, Izu Peninsula enjoys a moderate annual temperature variation of 4-30°C (39-86℉), making the overall weather relatively comfortable. August, the hottest month of the year, can see maximum temperatures reach above 35 degrees Celsius (95 degrees Fahrenheit), but sea breezes often bring a touch of coolness. Though winter becomes much chillier, there is no extreme cold: even in January - the coldest month, minimum temperatures rarely dip below freezing.

With the complex terrain, coastal and mountainous areas show distinct climatic features. For instance, in the coastal city Atami, temperatures mainly range from 3-29°C (37-84℉), while ones get lower at Mount Amagi, fluctuating between -5-23°C (23-73℉). Plus, the day-night temperature gap in the mountains is greater, up to around 14°C (57℉).

Precipitation

The annual precipitation of Izu Peninsula is relatively abundant, with an average of roughly 2,100-2,300 mm (83-91 in). Precipitation varies significantly across regions: persistently influenced by moist air currents from the Pacific Ocean, the area around Mount Amagi receives much more precipitation, totaling over 4,000 mm (158 in) yearly; in contrast, annual precipitation at Cape Irozaki, Matsuzaki and Toi averages under 2,000 mm (79 in).

Rainfall

Overall, rainfall mainly comes from summer and autumn, while winter is the driest season throughout the year. The rainy season here are typically from early June to mid-July, but it may start several days later, extending from mid-June to late June. During this period, light showers are most frequent, and there are consecutive cloudy days at times. With fickle weather conditions, you may encounter light rain, heavy downpours, overcast skies and sunny spells within a single day. And mountain areas may be foggy on rainy days.

Snowfall

Snowfall variations across different regions are pretty significant. In high-altitude areas like Mount Amagi, snow usually falls in January and February, when it’s more likely to see snow accumulation. However, it rarely snows in the warmer coastal areas. Even when it does, the snow cover is just a thin layer and melts away quickly. Cape Irozaki, the southernmost part of Izu, remains frost-free, making it the only exception in Japan.

When is the snowcap of Mount Fuji highly visible?

Generally speaking, the summit of Mount Fuji is covered in snow in late October - early May, but the best viewing time is late November - February. Thanks to low precipitation and sparse clouds, these periods have high visibility, allowing for a clear view of snowcapped Mount Fuji. You’re advised to visit Izu Panorama Park, Lover Cape or Mount Omuro before 9:00 or after 15:00 to admire this stunning landscape.

Humidity

Surrounded by sea on three sides, Izu Peninsula is relatively humid all year round, with monthly humidity ranging from 64% - 83%. In summer, especially during the rainy season, the air is sultry due to hot weather and high humidity; the humidity in winter drops a lot, but you don’t feel very dry.

Typhoon

Izu is typically attacked by typhoons between July and October, particularly in August and September, with nearly 1 typhoon making landfall on average. Strong winds and heavy rain caused by typhoons may disrupt your visit, so check the weather forecast frequently during these months.

Wind

Coastal and mountainous areas normally have stronger winds, resulting in lower apparent temperatures. Do note that the cable car service to Mount Omuro may be suspended for this very reason, so early confirm whether it opens before your departure.

When is the best time to visit Izu Peninsula?

February to May and October to early December are the best times for travel. These two periods, except for February, enjoy comparatively favorable temperatures and moderate precipitation. And most of the time, UV rays are not extremely intense and there is no need to worry too much about typhoons. 

Also, there are beautiful natural wonders, including cherry blossoms in early February - early April, plum flowers in mid-January - early March and autumn leaves in mid-November - early December. Ample activities and delicious food are well worth enjoying: Omuro Yamayaki Festival on the second Sunday of February, when the dry, dead grass is burned down to clear the way for fresh one; Hina Festival of Inatori Onsen in late January - March, showcasing hina dolls and hanging ornaments to pray for girls’ healthy growth; and Ise Lobster Festival in early October - November.

See more: Japan Weather & Shizuoka Weather

Izu Climate - Seasons, Travel Highlights and Advice

Floral Spring: March to May

Sunrise Time: 04:33 - 06:16
Sunset Time: 17:40 - 18:54
Daylength: 11 hours 25 minutes - 14 hours 21 minutes
Average Sunshine Hours: around 5.8 hours/day

 Weather
As the temperature gradually increases, everything rouses up from sleeping. In March - a transition from winter to spring, it still retains a chill with changeable temperatures. Daytime highs rise from 10-15°C (50-59℉) in early March to 20-25°C (68-77℉) in late March; nighttime lows are typically 5-10°C (41-50℉), but may hover around 0°C (32℉) in colder years. By April and May, temperatures get more stable: highs stay above 20°C (68℉), and the closer late May is, the more likely highs exceed 25°C (77℉); lows also climb to 15-20 (59-68℉).

Spring receives moderate rainfall with an average of roughly 187 mm (7.4 in) over14-16 rainy days. It often rains lightly, but there may be 1-2 days of heavy downpours each month with 40-80mm (1.6-3.2 in) daily rainfall. Rain frequently falls intermittently within a day. Compared to the other months, rainfall in March might last longer, normally for half a day or more. Spring has lots of overcast days, and sun protection is required in May with UV index of 8-10.

 Packing List
Clothes: Thin sweaters, lightweight down coats and thin-fleece jeans are suitable outfits in March. Wear hoodies or long-sleeved shirts., denim jackets or cardigans and jeans by April. In May, short sleeve shirts and thin sweatpants or long dresses are acceptable, and prepare a light layer to deal with temperature changes. From May, Mount Omuro looks like a matcha-tinted pudding. For attractive photos with this iconic background, white clothes are highly recommended. Considering you may walk a lot, comfy sneakers are the best.

Others: Remember to bring raingear, sunglasses and sunblock. Wear a hat with string against windy weather. There are lots of pollen between March and April, facial masks are indispensable for ones with a sensitive nose.

 Seasonal Highlights
1. In early March, Kawazu River are lined with early cherry blossoms and rape flowers. During late March through early April, a three-kilometer Sakura tunnel nearby the Izu-kogen Station and Sakura-no-Sato Park are both top spots to admire Sakura. From mid- to late April, Komuroyama Park transforms into a sea of azaleas.
2. Black Ship Festival takes place on the third Friday to Sunday of May, when you have a chance to enjoy a joint parade by American and Japanese soldiers, a firework display and music performances.

Lush Summer: June to August

Sunrise Time: 04:33 - 05:18
Sunset Time: 18:14 - 18:54
Daylength: 12 hours 56 minutes - 14 hours 21 minutes
Average Sunshine Hours: around 4.7 hours/day

 Weather
June in Izu is not very hot: day temperatures are around 25-30°C (77-86℉); after sunset, the temperature falls by 7°C (13℉), at 15-25°C (59-77℉). During the rest of time, maximum temperatures rarely drop below 30°C (86℉), and in hotter years, even climb to 35°C (95℉). However, early mornings and evenings get more pleasant, with temperatures staying around 25°C (77℉).

Summer is the wettest season all year round due to the rainy season. During this period, you do feel sticky, but compared to the oppressive heat of Tokyo, sea winds relieve this feeling somewhat. After the rainy season, there are more sunny days with extremely intense UV rays.

 Things You Need to Prepare
Outfits: Pack breathable, quick-drying clothes, including cotton-or-linen short sleeve shirts or tank tops and shorts or skirts. Air-conditioned indoor places are quite cool, so you’d better prepare a thin long-sleeved shirt. Shoes should be well-fitting, waterproof and non-slip. 

Accessories: Sun hats, sunglasses and sunscreen are necessities. A parasol is very practical on rainy and sunny days. To prevent sunstroke, bring a portable mini fan and regularly drink cool water. 

 Travel Recommendations & Advice
1. The seawater temperature averages 24-26°C (75-79℉) in July and August, and the official swimming season is mid-July to late August, which means there are on-duty lifeguards to protect your safety. Thus, these two months are favorable for all water sports, and recommended destinations are Shirahama Ohama Beach, Yumigahama Beach and Tatadohama Beach.
2. Summer is a real feast for fireworks lovers. Atami hosts 5-6 displays with 5,000 fireworks at 20:15-20:40: 1-2 in late July and 4 in August. At 20:00-21:00 on August 10, the sky is aglow with nearly 1,0000 fireworks during the Sea Fireworks Festival of Anjin Festival.
3. In June, no one can resist the beauty of hydrangea at Shimoda Park, which also provides the panorama of Shimoda Port and cityscapes.
4. In case of rain, arrange more indoor attractions: MOA Museum of Art, Numazu Deep Sea Aquarium, Kawana Stained Glass Museum and Izu Teddy Bear Museum.

Colorful Autumn: September to November 

Sunrise Time: 05:18 - 06:35
Sunset Time: 16:34 - 18:14
Daylength: 9 hours 59 minutes - 12 hours 55 minutes
Average Sunshine Hours: around 4.6 hours/day

 Weather
The summer heat lingers until mid-September: over 20 days see high temperatures of over 30°C (86℉), while the lows even stay around 25°C (77℉). By late September, it turns cooler: highs drop from an initial range of 25-30°C (77-86℉) to 15-20°C (59-68℉) in late November; lows fall from above 20°C (68℉) to 5-10°C (41-50℉). As November is approaching, the daily temperature variation gets larger, usually exceeding 10°C (50℉).

September and October have rich rainfall of 251 mm (9.9 in) and 245 mm (9.7 in) respectively, while November is considerably drier. Light rain predominates autumn, followed by heavy rain. The duration of rainfall is no more than 6 hours, but it’s common to see two showers throughout a day. Rainfall occurs more frequently in the mornings and evenings, and there may be 4-6 successive rainy days in the first two months. So, keep rain gear handy during your outdoor visit.

 What to Wear
In September, short-sleeved shirts and shorts still work well; with the UV index of 8, prepare sun-protective items. Long sleeve shirts or hoodies, cardigans and jeans are more suitable in October. In the first half of November, outfits in October may be acceptable; but during the rest of the month, pack thicker outerwear like padded coats or 3-in-1 jackets. Comfort is the first principle when choosing shoes, and they are better to be waterproof and anti-slip.

 Must-do Activities & Suggestions
1. Admire autumn leaves: You’re advised to appreciate colorful fall foliage at the following places: Atami Plum Garden and Shuzenji Temple both in mid-November to early December, as well as Kawazu Seven Waterfalls during late November through early December.
2. Savor seasonal seafood: Ise Lobster Festival is held from early October to November, when you can eat this top-class ingredient with chewy texture and sweet taste.
3. If your trip to Izu in 2026 falls during the peak period of typhoons - September, book a hotel with entertainment facilities and hot springs. This way, you won’t feel bored when hit by a typhoon during your stay.

Winter: December to February 

Sunrise Time: 06:16 - 06:35
Sunset Time: 16:34 - 17:40
Daylength: 9 hours 59 minutes - 11 hours 25 minutes
Average Sunshine Hours: around 6.5 hours/day

 Weather
In the first days of December, highs are mostly over 15°C (59℉), and lows usually exceed 5°C (41℉). In the rest time of the winter, the air is thick with chill: maximum temperatures often range from 10-15°C (50-59℉), while minimum ones fluctuate between 0-5°C (32-41℉). You experience a significant temperature swing between morning and evening, reaching 14°C (57℉) at most. 

Although monthly precipitation increases from 86 mm (3.4 in) in December to 121 mm (4.8 in) in February, winter still has the lowest precipitation over the year. The rain is mostly light and intermittent with the daily precipitation below 8 mm (0.3 in). Sunny days are very common in this season, leading to abundant sunshine hours.

 Clothing Guideline
Good indoor heating creates a huge temperature gap between indoors and outdoors, so layered dressing is a wise decision. Wear a sweater or fleece hoodie, topped with a down jacket. For your lower body, thick pants and hiking shoes are advised. Plus, light raincoats, beanies and scarves are also necessary.

 Travel Highlights
1. It’s advisable to see Kawazu cherry blossoms at Kinomiya Shrine or along the Aono River from early February, Atami cherry blossoms along the Itokawa Promenade in late January - early February, plum flowers at Atami Plum Garden in mid-January - early March, and daffodils at Cape Tsumekizaki Natural Park in Late December - January.
2. On chilly days, you can warm up at Atami Onsen or Inatori Onsen while appreciating spectacular ocean views.