Learn Hardcore Russian: Летом в пустыне часто бывает жарко.

Russian often uses the instrumental case without a preposition to talk about time when something happens, particularly with seasons and parts of the day:

летом – in (the) summer
зимой – in (the) winter
весной – in (the) spring
осенью – in (the) autumn
днём – in the daytime
утром – in the morning
вечером – in the evening

So Летом at the start of the sentence means “In summer / In the summertime”. Using just лето here would sound ungrammatical.

Could we say в лето instead of летом?

No, в лето is not the normal way to say “in summer” in modern Russian.

For seasons and similar time periods, Russian prefers those special instrumental forms (летом, зимой, etc.) with no preposition.

В + accusative/prepositional is used with many other time expressions:

в мае – in May
в 2020 году – in 2020
в субботу – on Saturday

But for seasons you should memorize the adverb-like forms: летом, зимой, весной, осенью.

What case is в пустыне, and why is that form used?

Пустыне is the prepositional case singular of пустыня (“desert”).

Dictionary form (nominative): пустыня
Prepositional (after в, “in”): (в) пустыне

You use the prepositional case after в when talking about being inside / in a place:

в пустыне – in the desert
в городе – in the city
в Москве – in Moscow

So в пустыне is literally “in (a/the) desert”. Russian does not have articles, so context tells you whether it’s “in a desert” or “in the desert” in English.

Why is there no word for “it” in this sentence?

Russian normally doesn’t use a subject pronoun “it” in sentences like “It is hot”, “It is cold”, “It is dark”, etc.

Instead, Russian uses impersonal constructions:

Жарко. – (It is) hot.
Холодно. – (It is) cold.
Темно. – (It is) dark.

In your sentence, часто бывает жарко literally is something like “often there happens to be hot”, but the natural English is “it is often hot”. The “it” is understood from the context (weather, conditions) and doesn’t need any word in Russian.

What exactly does бывает mean here, and can we leave it out?

Бывает is the 3rd person singular of бывать, an imperfective verb meaning roughly “to occur / to happen / to be (from time to time)”.

In this sentence, часто бывает жарко emphasizes repeated / typical situations:

Летом в пустыне часто бывает жарко.
→ “In summer it is often hot in the desert.”
(Hot weather regularly occurs there in summer.)

If you leave out бывает:

Летом в пустыне часто жарко.

This is also correct and very natural. It just states that it’s often hot there in summer, without explicitly highlighting the idea of “this happens / occurs”.

So:

With бывает – slightly more like “(there) tends to be heat”, habitual, descriptive.
Without бывает – a straightforward statement “it is often hot”.

Both are good; the difference is subtle.

Why can’t we use есть (the basic “to be” verb) instead of бывает?

In the present tense, Russian almost always drops the verb есть when it just means “is/are”:

Он студент. – He is a student. (No verb in Russian.)
Она дома. – She is at home.

So a form like есть жарко is not used.

Бывает here is not just a neutral “is”. It specifically adds the idea of something happening / occurring, often repeatedly. That’s why бывает works in this sentence and есть doesn’t.

For weather/conditions, you generally say:

Жарко. – It’s hot.
Иногда бывает жарко. – Sometimes it gets / is hot (from time to time).

What is the difference between жарко and жаркий? Why is жарко used here?

жаркий is an adjective: “hot” (describing a noun)
- жаркий день – a hot day
- жаркий климат – a hot climate
жарко is a predicative adverb / short form used to describe a state or condition:
- Сегодня жарко. – It is hot today.

In sentences about weather or general conditions, Russian prefers жарко (not жаркий by itself).

Your sentence describes a condition in the desert in summer, not directly modifying a noun, so жарко is the correct form:

Летом в пустыне часто бывает жарко. – “In summer it is often hot in the desert.”

If you wanted to use жаркий, you’d need a noun:

Летом в пустыне часто стоят жаркие дни. – In summer there are often hot days in the desert.

What part of speech is жарко? Is it an adverb?

Traditionally, жарко in this use is called a category-of-state word or predicative in Russian grammar. Functionally, for learners, you can think of it as an adverb used as a predicate:

It doesn’t change for gender, number, or case.
It describes a state (“it is hot”, “I feel hot”).

Examples:

Здесь жарко. – It is hot here.
Мне жарко. – I am hot / I feel hot.

So, while it looks like a regular adverb (ending in -о), its main job is to stand in the predicate position (“is hot”, “was hot”, etc.).

How flexible is the word order in this sentence?

Russian word order is fairly flexible, especially in simple statements like this. All of these are grammatically correct, with slight changes in emphasis:

Летом в пустыне часто бывает жарко.
(neutral, very natural order)
В пустыне летом часто бывает жарко.
– “In the desert, in summer, it is often hot.” (starting with the location)
Часто летом в пустыне бывает жарко.
– “Often, in summer, it is hot in the desert.” (emphasis on “often”)
Летом в пустыне жарко бывает часто.
– possible, but less natural in everyday speech; sounds a bit more marked or poetic.

The most typical everyday version is the original:
Летом в пустыне часто бывает жарко.

Why is it в пустыне and not на пустыне?

The choice between в and на with places is partly rule-based and partly idiomatic.

With many “environment” nouns like пустыня (desert), гора (mountain), лес (forest), you are usually inside / within that environment, so Russian uses в:

в пустыне – in the desert
в лесу – in the forest
в горах – in the mountains

На is more often used with surfaces, islands, events, some open areas, etc.:

на улице – in the street / outside
на пляже – on the beach
на острове – on the island

So for desert, normal Russian is в пустыне, not на пустыне.

What tense and aspect is бывает, and what does that tell us?

Бывает is:

Present tense
3rd person singular
From the imperfective verb бывать

Imperfective aspect in Russian focuses on habitual, repeated, or ongoing actions or states.

So часто бывает жарко literally suggests:
“(It) often happens / tends to be hot” – a typical, repeated situation in summer, not a one-time event.

How do you pronounce each word, and where is the stress?

Approximate pronunciation and stress (marked with ´):

Ле́том – LYE-tum (stress on Ле́)
в – short v sound, usually unstressed and linked to the next word: v
пусты́не – poos-TY-nyeh (stress on ты́)
ча́сто – CHA-stuh (stress on ча́)
быва́ет – bih-VA-yeht (stress on ва́)
жа́рко – ZHAR-kuh (stress on жа́)

Put together smoothly:
Ле́том в пусты́не ча́сто быва́ет жа́рко.