Осень пришла (“fall has arrived”), at least officially, and at least for those of us на северном полушарии (“in the Northern hemisphere”). Двадцать второго сентября было равноденствие (“The 22nd of September was the equinox”).

Cмотря где живёшь, ещё не очень холодно днём. (“Depending on where you live, it’s still not very cold during the day.”) А после осеннего равноденствия, темнеет всё раньше и раньше. (“But after the autumn equinox, it gets dark earlier and earlier.”) And here in the Washington DC area, деревья уже желтеют (“the trees are already turning color”).

The seasonal change offers a good excuse to talk about some expressions that relate to the weather and the sun’s rising and setting. Quite early on, students of Russian learn that the verb идти is often used when talking about precipitation: Идёт дождь (“It is raining”), Пошёл снег (“It started snowing”), Шёл град (“It was hailing”). And you may also be familiar already with Солнце светит (“The sun is shining”).

But there are quite a few others — and the good news (sort of) is that a lot of the relevant verbs are used only in impersonal constructions, at least in the context of weather. Which means that you’ve really only got three forms to worry about: the infinitive, the 3rd-singular imperfective present or perfective future, and the past neuter.

For instance, let’s go back to темнеет всё раньше. The verb темнеть (“to become darker”) isn’t used in the 1st or 2nd persons at all, and when the context is the general lack of illumination, it doesn’t take a nominative subject — so Темнеет! (“It’s getting dark!”) can be a complete sentence by itself. However, you can flesh out the sentence with adverbs or prepositional phrases expressing time and place: В комнате вдруг стемнело (“It suddenly got dark in the room”).

Just to be clear, темнеть CAN indeed take a nominative subject when you’re not talking about the absence of light. For example:

Он влил чернилы в стакан воды, и вода потемнела.
He poured ink into a glass of water, and the water turned dark.

And the word can also mean simply “to look/appear dark,” as in На фоне снега, избы темнеют (“Against the background of snow, the cabins/huts look dark”).

The opposite verb is (по)светлеть — “to become light (as in less dark)”. Once again, it’s possible in some contexts for this verb to take a nominative subject, as in Летом волосы у неё светлеют (“Her hair gets lighter in the summertime”). But it’s used impersonally when you mean illumination:

Мария вошла со свечкой, и в подвале посветлело. Maria came in with a candle, and it got brighter in the basement.

But make sure not to confuse (по)светлеть with (по)светить (“to emit light; to shine”). Thus, фонарик светит (“the flashlight is shining”), but на дворе светлеет (“it’s getting light outside”).

And don’t confuse either of these with the related pair рассветать/рассвести — which means “to be dawning, to be daybreak”, and is used only impersonally:

Весной, рано рассветает.
It dawns early in the springtime.

Мы не поедем пока не рассветёт, из-за вампиров.
We won’t set out until the dawn comes, on account of vampires.

Of course, if you happen to be a vampire, then your alarm clock goes off not на рассвете (“at sunrise”), but на закате (“at sunset”). After the sun has gone down, but before it’s totally dark, then it’s сумерки (pl. only, gen. сумерек) — “twilight.” And there’s even a specific verb for the falling of dusk/twilight: смеркаться/смеркнуться. Yet again, you use it impersonally: Ещё не смеркнулось, “It’s not full twilight yet.”

Besides the shorter days and earlier sunsets, autumn also means the gradual arrival of cold weather — and of course there’s an impersonal verb for this: (по)холодать. For instance, На дворе холодает — тебе надо одеться по-теплее. (“It’s getting cold outside — you’d better dress a bit more warmly.”)

As the nights are getting colder, я думаю переместить цитрусы с балкона в комнату, “I’m thinking about moving my citrus plants inside from the balcony.” (I have a lime tree that’s over 9 years old, plus two small kumquats.) For now, they’re okay, but they could die если ночью морозит (“if it’s below the freezing point at night”), because цитрусы не выдерживают инея (“citruses do not tolerate frost”).

That verb морозить is a bit different from some of the others I’ve mentioned because it can also be used transitively, suggesting “freeze someone/something to the point of damage.”

Ой, мороз, мороз — не морозь меня!
“Oy, frosty weather — don’t chill me so bitterly!”

Indoors, my plants will be safe from мороз (“freezing weather”), but В нашем доме центральное отепление ещё не включили (“they haven’t turned on the central-heating yet in our building”), and I often have to wear sweaters at home, потому что в спальне сквозит (“because it’s drafty in the bedroom”). You may already know the preposition сквозь (+ acc.), which means “through,” especially with emphasis on squeezing through a tight opening. So how appropriate that the verb сквозить — when it’s impersonal, with no subject — means “to be drafty, to have a draft.” An approximate synonym would be a construction such as В спальне дует от окна (“In the bedroom it is blowing from the window”). In that example, дуть (“to blow”) is impersonal, but you can also use it with subjects: cильный ветер дует с востока (“a strong wind is blowing from the east”), or я подул на суп (“I blew on my soup a bit”).

Finally, if you forget any of the specific verbs discussed here, remember that in most cases it’s perfectly okay to use the generic verb становиться/стать (“to become”) followed by a comparative adjective. Thus, На улице становится темнее (“It’s becoming more dark outside”) is a synonym for На улице темнеет (“It’s darkening outside”).