Seirō, Japan — Weather in January 2027

Climate Overview

Seirō, Japan in January has cold conditions, with highs averaging around 3.5°C (38°F). Rain falls on about 27 days this month, totalling around 237 mm. Sea temperature stays cool at 11.3°C (52°F).

This month falls at the middle of Winter. Cold conditions dominate the month.

Temperatures remain fairly steady throughout January, with daily highs around 4°C (39°F).

January sees fairly even rainfall, totalling about 239 mm across the month.

The warmest days tend to fall around the 1th, averaging 4°C (39°F).

Compared to December, this month is about 3°C cooler with 0 fewer rainy days.

Monthly January Averages

Temperature

4°C / -1°C

Feels Like

-1°C / -6°C

Rain

27 days · 237 mm

Sunshine

5.8h / day

Humidity

82% — Very Humid

Wind

22 km/h

Wind Direction

W (278°)

Gusts

46 km/h

Daylight

9.9 h

Cloud Cover

79%

Clear Sky Days

UV Index

2.5 — Moderate

Sea Temperature

11°C

Dew Point

-2°C — Dry

Moon Phase

First Quarter · 46%

Snow Days

23 days · 82.1 cm

Frost Days

22 days

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

High Low

Daily Precipitation

Rainfall

Daily Sunshine

Sunshine

Daily Wind Speed

Wind Speed

Sun Position

Sunrise 06:58

Daylight 9.8h

Sunset 16:47

What to Expect

Cold daytime highs of 4°C (38°F) mean shorter outdoor excursions with warming breaks. Keep afternoons flexible as tropical showers are common — they typically clear within an hour.

Wet weather can spread across much of the day, so it is best to keep outdoor plans flexible.

1 of the last 5 yearly records were warmer than this month's long-run average.

Compare Months

Month	Temp	Feels Like	Rain	Sun	Humidity	UV	Status	Details
January	4°C / -1°C	-1°C / -6°C	27days (237 mm) Wet	5.8h Fair	82% Humid	2.5 Moderate	Wet	View Details
February	4°C / -1°C	0°C / -6°C	22days (161 mm) Wet	7.4h Good	79% Humid	3.5 Moderate	Wet	View Details
March	10°C / 2°C	7°C / -2°C	18days (136 mm) Wet	8.1h Good	76% Humid	4.6 Moderate	Wet	View Details
April	16°C / 7°C	14°C / 4°C	15days (132 mm) Wet	9.2h Good	76% Humid	5.7 High	Fair	View Details
May best	21°C / 12°C	22°C / 11°C	14days (134 mm) Wet	9.5h Good	77% Humid	5.7 High	Excellent	View Details
June best	24°C / 17°C	27°C / 18°C	15days (160 mm) Wet	9.6h Good	82% Humid	6.6 High	Excellent	View Details
July	28°C / 22°C	33°C / 25°C	18days (256 mm) Wet	9.5h Good	84% Humid	6.9 High	Wet	View Details
August	30°C / 23°C	35°C / 27°C	18days (238 mm) Wet	9.9h Good	83% Humid	7 High	Wet	View Details
September best	26°C / 19°C	29°C / 21°C	16days (193 mm) Wet	8.1h Good	82% Humid	5.6 High	Excellent	View Details
October best	19°C / 13°C	19°C / 11°C	15days (171 mm) Wet	7.1h Good	80% Humid	4 Moderate	Good	View Details
November	13°C / 7°C	11°C / 4°C	20days (191 mm) Wet	6.8h Fair	79% Humid	2.8 Moderate	Wet	View Details
December	7°C / 2°C	3°C / -3°C	27days (277 mm) Wet	5.6h Fair	83% Humid	1.8 Low	Wet	View Details

What to Wear

Full winter gear is a must — insulated coat, thermal base layers, warm hat, gloves, and waterproof boots.

A waterproof jacket or compact umbrella is recommended for occasional showers.

Packing List

Warm coatThermal base layersScarf & glovesUmbrellaWaterproof jacketWaterproof shoes

Frequently Asked Questions

Expand all

Is January a good time to visit Seirō?

January is typically wet for visiting Seirō, with average highs of 4°C (38°F) and around 27 rainy days. Seirō, Japan in January has cold conditions, with highs averaging around 3.5°C (38°F). Rain falls on about 27 days this

Does it rain a lot in Seirō in January?

Seirō typically sees around 27 rainy days in January with 237 mm (9.3 in) of total rainfall. Pack a waterproof jacket.

Does it get cold at night in Seirō in January?

Yes, nights in Seirō during January are cold, averaging -1°C (30°F). Pack warm layers and a coat for evenings.

What should I pack for Seirō in January?

With highs of 4°C (38°F) and lows of -1°C (30°F) in January, we recommend: Warm coat, Thermal base layers, Scarf & gloves, Umbrella, Waterproof jacket. Comfortable walking shoes are essential.

Is January among the best months weather-wise in Seirō?

January is not the most favourable month weather-wise in Seirō. Consider visiting during months with milder temperatures or less rainfall for a better experience.

What is the UV index in Seirō in January?

The average UV index in Seirō during January is 3 (moderate). Sunscreen and sunglasses are recommended during midday hours.

How many hours of daylight are there in Seirō in January?

Seirō gets approximately 10 hours of daylight per day in January, with around 6 hours of sunshine.

Does it snow in Seirō in January?

Yes, Seirō typically sees around 23 snow days in January with roughly 82 cm (32 in) of snowfall.

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