A Pasqua, se il tempo è bello, mangiamo in giardino; a Ferragosto, invece, andiamo in spiaggia.

With many feast days and holidays, Italian often uses a to mean at / on that occasion.

• a Pasqua = at Easter / on Easter
• a Ferragosto = at Ferragosto / on August 15th

This is a normal pattern with certain holidays and special days.

Because Pasqua and Ferragosto are being used as names of holidays, not as common nouns with a specific article.

So Italian says:

• a Pasqua
• a Ferragosto

not usually alla Pasqua or al Ferragosto in this kind of sentence.

Ferragosto is an important Italian holiday on August 15th. It is associated with summer vacations, trips, beaches, outdoor meals, and generally the height of summer in Italy.

So in this sentence, a Ferragosto naturally fits with andiamo in spiaggia.

Yes, tempo can mean both time and weather, depending on context.

In the expression il tempo è bello, it clearly means the weather is nice.

This is very common in Italian:

• Che tempo fa? = What’s the weather like?
• Il tempo è brutto. = The weather is bad.

Italian normally uses bello to describe pleasant weather:

• bel tempo
• il tempo è bello

Using buono here would sound unnatural. Bello is the standard adjective for nice / good weather.

Italian often uses the present tense where English might use either the present or the future.

In this sentence, the present can express:

• a habit or usual pattern
• a typical arrangement
• something seen as a regular fact connected with those holidays

So mangiamo and andiamo do not have to mean only we are eating / going right now. They can mean we eat / we usually eat / we go in that situation.

Because this is a normal, real condition: if the weather is nice.

Italian usually uses the indicative after se in straightforward real conditions:

• se il tempo è bello, mangiamo in giardino

The subjunctive is not used here. This is one of the most basic and common se + indicative patterns.

Italian often leaves out subject pronouns because the verb ending already shows the subject.

• mangiamo = we eat
• andiamo = we go

So noi is unnecessary unless you want extra emphasis or contrast.

In Italian, some place expressions can appear without an article when the place is understood in a general or natural way.

• mangiare in giardino = to eat in the garden
• andare in spiaggia = to go to the beach / onto the beach

This sounds idiomatic and natural. Adding an article is sometimes possible in other contexts, but these article-less versions are very common.

Invece means instead / on the other hand / by contrast.

Here it marks a contrast between the two occasions:

• At Easter ...
• At Ferragosto, instead / by contrast ...

It helps show that the second half is a different situation from the first.

That position is very common because invece works like a parenthetical contrast marker.

The structure is:

• a Ferragosto = time expression
• invece = contrast marker
• andiamo in spiaggia = main clause

Putting invece between commas makes the contrast especially clear. Italian has some flexibility here, but this placement is very natural.

The punctuation helps organize the sentence clearly.

• A Pasqua,: the comma separates the introductory time phrase.
• se il tempo è bello,: the second comma closes the conditional clause.
• ;: the semicolon separates two closely related main parts of the sentence.

A semicolon is useful here because the two halves are parallel:

• A Pasqua ... mangiamo in giardino
• a Ferragosto, invece, andiamo in spiaggia

It is stronger than a comma but not as final as a full stop.

It can mean either, depending on context.

Very often, a phrase like a Pasqua is understood as at Easter / on Easter, and it may refer to:

• a particular Easter being discussed, or
• the usual custom connected with Easter

In this sentence, because the present tense sounds habitual, many learners would read it as a general or customary pattern: At Easter, if the weather is nice, we eat in the garden.

Literally it is we eat in the garden, but in real life Italian mangiare can often imply having a meal, especially from context.

So depending on the situation, an English speaker might naturally understand it as:

• we eat in the garden
• we have lunch in the garden
• we have our meal in the garden

The Italian itself stays broad and does not specify which meal unless context does.