Weather in Perth in July

Shoulder season. July sits in between. You will get good days and you will lose some. You should expect rain on 15 days of the month, which is more days wet than dry.

July ranks 12 of 12 — near the bottom of Perth's year. January is the month that works, and the swing between the two is 34 points, which is a different holiday rather than a slightly better one.

Rain on 15 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 17.6 °C days and 13.6 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: the day barely swings — 4 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest July day reached 22.1 °C and the coldest night fell to 8.8 °C, and the wettest single day dropped 48 mm — roughly 38% of the month's rain in one day.

July is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest July on record still delivered 207 mm against 51 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 128 mm average is a reasonable planning figure, not a promise.

Wind sits around 18.6 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity is unremarkable at 73%.

How July sits in the year

Temperatures hold steady either side: 18.9 °C in June, 17.6 here, 17.6 in August. Nothing about the timing within the month matters much.

Daylight in July

July sits at the dark end of Perth's year — 10.2 hours of daylight against 14.2 at midsummer, gaining 0.4 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 20.4 °C in July — swimmable, but it takes a moment to commit. The sea peaks at 22.9 °C in March and bottoms out at 19 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

July in Perth versus nearby

If Perth is one option among several, the nearby comparison is worth making. Bunbury is close enough to be a coin toss — within a degree on temperature, 2 days more rain. Geraldton is a better bet in July — within a degree on temperature, 4 days less rain.

So: July is a compromise. January is 34 points better and is what Perth is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Perth

See all twelve months in Perth, or where else to go in July.