washing netilas yadayim on shabbos

Rain is diffferent.

He is not doing an action with his own hands (the rain falls from the sky on its own, as opposed to me pouring water on my clothing).

With rain – The wetting of his clothing is against his will; he doesn’t want it to happen, and would prefer that it not happen.

The rain soils his clothing, as opposed to improving them.

It is impossible to avoid the rain.

Interestingly, the poskim discuss why it’s not a problem of carrying if one’s clothes get wet in the rain.

“But when you open or close the door in the rain, you are with your own hands causing the water collected on the door to fall off.”

On the doorknob? The doorknob is a makom pattur, so it’s OK.

“With getting your sleeves wet when washing, you’re also wetting your clothing against your will.”

According to some poskim, it is forbidden, on Shabbos and yom tov, to cause even a clean garment to become wet. Even a clean garment is improved with additional laundering – and wetting a garment is considering the first step in the laundering process. I already explained the numerous differences between this and walking in the rain.

As far as sleeves are concerned, some poskim say that going out in rolled-up sleeves is considered carrying (if he would prefer that the rolled-up material not be there; the rolled-up material is not actually covering his body or serving any other function – therefore, it is a burden and you are transgressing the prohibition of carrying in a public domain on the holy Sabbath. Rav Moshe zatzal held like this.

From Limud Torah Web site: The Maharam did not wipe his hands on a towel until he removed most of the water from them by vigorously flaying his hands. He was worried that an excess of water would result with transgressing the Issur of laundering the towel on Shabbos. The Mechaber concludes that it is a good thing to keep this Chumra. The Rama says there is no reason to keep it, for even if there is some excess water which gets on the towel, it is only done in a manner which will make the towel dirtier.

The Magen Avraham says that the reason why the Mechaber holds this to be a Chumra, is since there is no dirt on the towel, soaking it is not considered laundering. The Tosfos Shabbos asks why in Simon 319 the Mechaber seems to hold that someone must be careful M’Iker Hadin not to soak something even when it does not have dirt on it. So we must conclude the Mechaber holds according to the reasoning of the Rama here, and considers wiping one’s hands on a towel to be dirtying the towel.

147: Walking in the rain is OK, so you’re off the hook there.

By getting the sleeve wet (when washing your hands), the fabric is improved by being laundered, so that is questionable (if it’s OK).

It doesn’t go by what’s “uncomfortable.” Getting your teeth pulled may be uncomfortable, and against your wishes, but it’s not allowed because of gozez.

Drawing blood may be uncomfortable and against your wishes, but it’s not allowed on Shabbos.

I am almost certain that Rav Moshe zt”l wore short-sleeved shirts.

But, then again, some forbid men from wearing wristwatches (this is a Chazon Ish thing).