Sun Hat on Shabbat

Is there a prohibition on wearing a sun hat on Shabbat (intended for shade)?

Shalom,

If the width is less than a tefach, it is permitted. One may be lenient up to a measurement of 9.6 cm.

And one should not protest against those who are lenient in this matter, even if it is more than that.

Mishnah Berurah Siman 301, Seif 52, Seif Katan 152:

Because of the prohibition of Ohel (making a tent). Even though a tent normally requires walls (defanos), nevertheless this is considered a temporary ohel and is rabbinically prohibited, since the brim was made to provide shade and protection from the sun.

And a hat known as a "Bräitelich", even though it extends outward from the head with a width of a tefach (handbreadth), and people customarily are lenient regarding it, the later authorities (Acharonim) have given several reasons for permitting it. One reason is that since it is not stiff and bends downward, there is no concern of prohibition — and this applies when it does not contain any stiff paper. And even if it is stiff, the intent in wearing it is not for shade, but simply to cover the head.

Also, if the brim is sloped, there is also reason to argue that it is not considered an ohel in such a form. The Eliyah Rabbah writes that the common practice is based on reliance on the view of Rashi, who hold that there is no ohel prohibition in wearing a hat at all. According to this, even with a kapelush whose brim is a tefach wide, one should not protest in places where people are accustomed to be lenient — even though presumably such a brim was made for shade.

However, in places where they are not accustomed to be lenient, one should certainly be stringent in accordance with the Shulchan Aruch (which follows the view of the Ra'ah, Rambam, Aruch, Rabbeinu Tam, and the Ra'avad), not to wear such a wide kapelush on Shabbos. Also, in the writings of the Arizal, such a kapelush is forbidden.

There are those who refrain from placing the tallis over the Bräitelich hat on Shabbos, in order that the tallis should not form two sides (like tent walls). See the Magen Avraham, who questions the reasoning of this practice, and the Machatzis HaShekel explains it.

And from this evolved the current practice not to cover their heads at all with the tallis during Shabbos prayers — even over a small hat — and this practice has no basis or reasoning.

Regarding the prohibition of carrying a parasol, which is made to shield a person from the sun or rain, we wrote about this in detail in Siman 315.