Umi in Winter
In winter (December, January and February), Umi sees average daytime highs around 11°C and overnight lows near 3°C, with 203 mm of precipitation over about 28 wet days across the season. It is the coldest season of the year and the driest season of the year.
Across winter, daytime highs hold fairly steady around 11°C. The sky is clear or mostly clear about 19% of the time across winter, and the air most often feels dry.
Winter is Umi's weakest season of the year to visit on our travel score. For the whole year in context, see Umi's year-round climate.
- Avg daytime high
- 11°C
- coldest season of the year
- Avg overnight low
- 3°C
- Precipitation
- 203 mm
- 28 wet days
- Avg wind
- 9 km/h
- Travel score
- 2.7
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Umi in Winter
Across winter, daytime highs hold fairly steady around 11°C.
A typical winter day in Umi reaches about 11°C and drops to 3°C overnight. The warmest of the three months is December, the coolest January.
How winter really feels in Umi
Once humidity and wind are folded in, winter brings about 0 days that feel above 32°C and 31 that feel at or below 0°C.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Umi weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 10° / 2° | 63 | 9.6 | 1.5 | 10 | 2.1 |
| Feb | 11° / 3° | 71 | 9.1 | 1.2 | 10.8 | 2.6 |
| Mar | 14° / 6° | 115 | 11.6 | 0.2 | 11.7 | 4.1 |
| Apr | 19° / 10° | 130 | 11.1 | 0 | 12.8 | 5.9 |
| May | 24° / 15° | 147 | 10.6 | 0 | 13.7 | 6.6 |
| Jun | 27° / 20° | 305 | 15.8 | 0 | 14.2 | 5.3 |
| Jul | 30° / 24° | 287 | 17.5 | 0 | 14 | 3.9 |
| Aug | 32° / 24° | 171 | 15.1 | 0 | 13.2 | 3.7 |
| Sep | 28° / 21° | 179 | 12.8 | 0 | 12.2 | 5.5 |
| Oct | 23° / 15° | 101 | 8 | 0 | 11.2 | 7.2 |
| Nov | 18° / 9° | 86 | 8.6 | 0 | 10.3 | 5.8 |
| Dec | 12° / 4° | 69 | 9.3 | 0.6 | 9.8 | 3.3 |
Cloud cover in Winter
The sky is clear or mostly clear about 19% of the time across winter.
Chance of precipitation in Winter
Umi gets around 203 mm of rain and snow over 28 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 9 km/h across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 54 min in early December to 11 h 12 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.6 kWh/m².
Hazard calendar for Umi
In winter, Umi overlaps its pacific typhoon season. The full year is below, with each hazard's peak months called out.
Umi sits in the Pacific typhoon belt; the season peaks July–October.
Umi's rainy season runs May–September, when most of the year's rain falls.
Is winter a good time to visit Umi?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Umi.
What to pack for Umi in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Umi sees daytime highs around 11°C and nights near 3°C. Pack a warm layer. Worth having: rain gear. About 28 days see rain.
Sea temperature near Umi in Winter
The nearest coast averages about 16°C across winter — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 36 km away) is warmest in August at about 27°C and coldest in February near 14°C.
It's comfortable for a long swim from Jun 7 to Nov 19 — about 5.5 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 14 | 14 | 15 | 18 | 21 | 25 | 27 | 26 | 23 | 20 | 18 |
| Comfort | Cool | Bracing | Bracing | Cool | Cool | Refreshing | Warm | Warm | Warm | Refreshing | Refreshing | Cool |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 14 | Bracing |
| Mar | 14 | Bracing |
| Apr | 15 | Cool |
| May | 18 | Cool |
| Jun | 21 | Refreshing |
| Jul | 25 | Warm |
| Aug | 27 | Warm |
| Sep | 26 | Warm |
| Oct | 23 | Refreshing |
| Nov | 20 | Refreshing |
| Dec | 18 | Cool |
UV index in Umi in Winter
Clear-sky midday UV across winter averages around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Umi peaks around July 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 3 | 4 | 6 | 8 | 8 | 7 | 9 | 9 | 9 | 6 | 4 | 3 |
| Level | Moderate | Moderate | High | Very high | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 3 | Moderate |
| Feb | 4 | Moderate |
| Mar | 6 | High |
| Apr | 8 | Very high |
| May | 8 | Very high |
| Jun | 7 | Very high |
| Jul | 9 | Very high |
| Aug | 9 | Very high |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Air quality in Umi in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Umi is worst in April — around 25 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 12 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 17 | 20 | 25 | 25 | 23 | 18 | 13 | 15 | 13 | 12 | 15 | 14 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 17 | Moderate |
| Feb | 20 | Moderate |
| Mar | 25 | Moderate |
| Apr | 25 | Moderate |
| May | 23 | Moderate |
| Jun | 18 | Moderate |
| Jul | 13 | Moderate |
| Aug | 15 | Moderate |
| Sep | 13 | Moderate |
| Oct | 12 | Moderate |
| Nov | 15 | Moderate |
| Dec | 14 | Moderate |
Where is Umi?
Umi sits at 33.6°N, 130.5°E, 41 m above sea level, in Japan. The nearest listed city is Sue, 3.0 km away.
Topography around Umi
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Umi.
Within 3 km, the terrain around Umi has significant variations in elevation — a maximum elevation change of 362 m around an average of 85 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 922 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,509 m.
The land around Umi is covered by artificial surfaces (54%) and trees (38%) within 3 km, trees (53%) and artificial surfaces (32%) within 16 km, and water (43%) and trees (40%) within 80 km.
Japan travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 100 V · 50 / 60 Hz
- Prices
- ≈ 65% of US
- price level, 2025
- GDP per capita
- $35,951
- 2025
- Happiness
- 6.1 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.2
- per 100k, 2023
- Road deaths
- 3.6
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Very low
- EF EPI 446
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Umi (33.5683°, 130.5101°, elevation 41 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.