Learn Portuguese (Portugal): As ruas são bonitas em julho e agosto. - The streets are beautiful in July and August.

In Portuguese, the months of the year (like julho and agosto) are always written with lowercase letters, unlike in English. They are only capitalized if they happen to be the very first word of a sentence.

Why do we use the word "em" before the months instead of "no" or "na"?

The word em simply means "in". While you have probably seen em combine with words for "the" to make no or na (meaning "in the"), we don't say "in the July" in Portuguese. Since we just need the word "in", we use the plain preposition em right before the month.

If the streets are only beautiful in July and August, shouldn't we use "estão" (temporary) instead of "são" (permanent)?

This is a great catch! While estar is used for temporary states, ser (the verb for são) is used to state facts or defining characteristics. Here, the speaker is stating a general, predictable fact about how the streets always look every year during those specific months, so são is the most natural choice.

Why does the word for beautiful end in "-as" here (bonitas)?

In Portuguese, describing words (adjectives) must match the noun they describe. Because ruas (streets) is a feminine and plural noun, the base word bonito must change to its feminine plural form, bonitas.