English equivalent of *refrán*, which is less formal than a proverb

Solution 1:

I think you just want to use saying (which is used in your definition of refrán):

A saying is a sentence that people often say and that gives advice or information about human life and experience.
We also realize the truth of that old saying: Charity begins at home.
_Collins

In a list of words related to proverbs, saying is defined as:

A short well-known expression — a pithy remark of wisdom and truth or a general advice.
Example: The road to hell is paved with good intentions.
_{Smart Words}

Solution 2:

If you don't like saying (which is jxh@'s excellent suggestion), how about an adage:

a saying often in metaphorical form that typically embodies a common observation. Example: She reminded him of the adage: "A penny saved is a penny earned."

_{Merriam-Webster}

Or possibly an aphorism:

1 : a concise statement of a principle

2 : a terse formulation of a truth or sentiment : adage. Example: the high-minded aphorism, "Let us value the quality of life, not the quantity"

3 : an ingeniously terse style of expression : aphoristic language

_{Merriam-Webster}

I think adage is probably closer to the weather examples.

Solution 3:

Perhaps mildly obscure in today's language but I'm astonished that nobody has mentioned the word refrain yet. It has two meanings, but it's the noun we're interested in, which appears primarily in musical terminology:

²refrain

/rɪˈfreɪn/

1. a regularly recurring melody, such as the chorus of a song

2. a much repeated saying or idea

Merriam-Webster

This corroborates with the given suggestion of saying above. With cursory research it is difficult to find a citable source for the Spanish, but it appears that refrain's etymological root is the same as the given refrán:

²refrain

Middle English refreyn, from Middle French refrain, alteration of Old French refrait melody, response, from past participle of refraindre to break up, moderate, from Vulgar Latin *refrangere, alteration of Latin refringere

Merriam-Webster

refrán

Borrowed from French refrain, from Latin re- (“back, again”) + frangō (“break”).

Wiktionary

frangō being a conjugation of frangere, whose derived terms include refringo, which is itself etymologically composed of 're-' and 'frangō' and is a conjugation of the Latin refringere which was mentioned by Merriam-Webster regarding the origin of the English 'refrain', above.

This is why I think 'refrain' may actually be the closest equivalent word, even if it isn't particularly widely used outside of musical terminology.

Solution 4:

In addition to 'saying' you could use 'saw':

saw: a sententious saying; maxim; proverb

Usually combined with 'old':

He could muster an old saw for every occasion.

dictionary.com

Solution 5:

Platitude is a possible one that occured to me.

Platitude

/ˈplatɪtjuːd/

Noun

A remark or statement, especially one with a moral content, that has been used too often to be interesting or thoughtful.

google.com