Shikoku winter - Clear or cloudy?

January and February seem to have few rainy days. Is there usually a blue sky or are the days overcast?

I'm thinking of visiting the top end of the island plus Naoshima and Okayama.

Details depend on the exact location, but the weather is generally very good during winter thanks to the Chugoku mountain range blocking off the moist air that keeps hitting Japan from the north during most of the winter.

Takamatsu in early February:
Sunny days: 60%
Rainy days: 19%

Matsuyama in early February:
Sunny days: 57%
Rainy days: 22%

Okayama in early February:
Sunny days: 64%
Rainy days: 16%

(A sunny day is defined as a day when the sun shines for at least 40% of the daytime)

Thank you Uji. Which website do I look at to find the places and months with the sunny days?

Here you go:
https://www.data.jma.go.jp/obd/stats/etrn/index.php

Thank you Uji. This is a useful site but no way to sort the data. The area around Shizuoka seems sunny in winter too. Are there other places?

The Kofu plain and Gunma are, I believe, the sunniest places in Japan in winter.