Difference between “s'attendre” and “attendre”

Attendre et s'attendre, both can be "to expect".

"Nous pouvons attendre de la pluie plus tard."

Is not correct.

"Nous pouvons nous attendre à de la pluie".

Is correct.

Nous pouvons attendre quelqu'un. (wait for, expect someone)

Et s'attendre à quelque chose. (to expect)

J'attends Gaston, je m'attends à ce qu'il soit en retard.

https://www.anglaisfacile.com/exercices/exercice-anglais-2/exercice-anglais-8444.php

attendre se traduit par wait lorsqu'on se réfère à la durée.

Dans le sens de s'attendre à il faut utiliser expect.

· she has not arrived yet. I can't wait any longer, I am going back home. Je ne peux pas attendre plus longtemps.

· I'm expecting a letter from my mother today.I hope I'll have it.

J'attendais une lettre de ma mère
If it's a disappointed expectation: Je m'attendais à une lettre de ma mère

Expect se traduit souvent par :

             Supposer, penser, prévoir, etc.

· I expect she will meet us again (je pense qu'elle reviendra nous voir)

· I didn't expect to fail that exam (je ne m'attendais pas à échouer à cet examen)

No, only the first sentence is correct in order to translate "to expect", in almost all cases.

The second one fits no common contexte (science fiction); if speaking about the weather you can find this idea of expectation in "attendre" but you can't use "pouvons"; however, I'm afraid it's limited to the context of the weather, essentially.

• Nous attendons de la pluie plus tard.
  We believe that we should have rain later. • We're expecting rain later.

• Votre belle mère ? Nous l'attendons d'un moment à l'autre ! Justement elle vient nous visiter aujourd'hui.
  Your mother-in-law? We're expecting her any minute now! She is in fact paying us a visit today.

COMPLEMENT OF EXPLANATION

The form "attendre qqc" is limited to this context, or rather to this type of context of which the weather is typical; it's a form that is not used to express the idea of "expecting" in the general, abstract case. For instance "Il attend une amélioration des conditions de travail." does not mean "He thinks there will be improvements soon", but instead, simply, it means that "He is refraining from doing something until improvements are realised.". What he is refraining from must be made clear in the context.

"Pouvoir s'attendre à" and "s'attendre à" do not say the same thing. Here, you want the strict notion of expectation to be rendered; of course there is no great difference and you could use the first form ("pouvoir"); nevertheless, to take up your sentence ("nous pouvons…) it means rather "We are justified in expecting rain.", "We have every Reason to believe there will be rain soon."