That applies to bike touring as well.
One topic not discussed is the risk of riding in moderate to heavy rain.
A number of things happen when it is raining fairly hard.
Visibility is reduced - Stopping distances increase - For cars and bikes.
Also, drivers' and cyclists' moods change - and mood affects decisions.
That is why I usually opt NOT to ride when it is raining.
If it looks to be an all-day rain - that's a good day to take off.
Except for the coasts - most summer rain comes in squalls or storms.
So it clears up - you ride a while - and you chill when it starts up again.
From the Atlantic to eastern Kansas there are frequent towns.
In remote areas of the West, it tends to be dry with occasional big storms.
In western Oregon, summers tend to be quite dry, too.
I always tour with a decent jacket that has two purposes - warmth and water repellency.
(I also carry a synthetic long-sleeve turtleneck or fleece.)
I have never found an ideal jacket - I currently have a North Face Hyvent.
I sweat like a pig in totally waterproof jackets - which defeats the purpose, eh?
And repellent jackets will not keep you dry for hours in a downpour.
Gore-Tex (aka Leak-Tex) is way overrated in my book.
Also - bright colors are good for visibililty.
In addition, some kind of wind pants are important.
Again, these will be nice on cool/cold mornings in the West.
Like the jacket - 100% waterproof will mean you sweat.
Water repellent and breathable are the two parameters.
You can usually find discount prices at places like Campmor.
My rainwear/coldwear is significantly more robust than that described above.
However, most of my touring of late has been in the West, Canada, and Alaska.
I have opted for a compromise - both in weight and cost.
Not the cheapest and flimsiest - but nothing close to expedition quality.
Still, I like having the extra assurance against bad weather.
And when it really gets bad - - I hole up.