Katoomba (Blue Mountains) weather in September

September in Katoomba: cool, a little rain, with clean air — an excellent time to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

Katoomba🇦🇺 Australia · Australian East Coast · Trekking88
  1. 79Jan
  2. 81Feb
  3. 79Mar
  4. 90Apr
  5. 85May
  6. 78Jun
  7. 76Jul
  8. 82Aug
  9. 88Sep
  10. 92Oct
  11. 88Nov
  12. 86Dec

#3 of 12 months in Katoomba · #326 of 1413 destinations to visit in September · comfort 88/100 (tier A)

Days
16°C
Nights
6°C
Wet days
8
Sun
9.8 h
Humidity
68%
Daylight
12 h
Katoomba, Australia
Photo: Nirmala Rao Dhanawada · Pexels

Traveller notes on Katoomba in September

Katoomba-forum threads on September temperatures describe sunny, mild days as the norm, one visitor reporting comfortable t-shirt-and-shorts weather during the day on a walking tour, though nights stayed genuinely cool enough to need warmer layers even in otherwise mild conditions. Posters call the Blue Mountains reliably a few degrees cooler than Sydney regardless of season, worth factoring in for anyone day-tripping from the city without packing accordingly. Regulars describe September as sitting within a genuinely favorable, comparatively settled stretch, precipitation totals running low and rainy days comparatively rare compared to other months. Layers are standing advice throughout, a light jacket or jumper for the evening standard even on a warm afternoon. Posters call Scenic World and the surrounding lookout trails comfortable September picks regardless of exact conditions. The record: 15.8C days feeling like 14C, 5.8C nights, a low 68 percent humidity and 8.7 hours of sun.
KatoombaSeptemberRegular · September · 1 month ago · Read more on Tripadvisor ↗

Other months in Katoomba

Katoomba-forum threads on Blue Mountains summer describe conditions as reliably cooler than Sydney regardless of the calendar, posters calling a properly cold February day entirely possible even at the height of peak summer. Regulars call warm layers standing advice year round, several visitors surprised by needing a jacket in what they expected to be a blazing month. Posters describe storms as genuinely common this time of year, first-timers advised against planning a trip specifically for the views if the forecast already looks unsettled. Regulars call fog a real factor too, the famous lookouts occasionally delivering little beyond grey mist on an unlucky day. Posters recommend flexible plans and a backup indoor activity given how unreliable February weather runs. The record: 23.9C days feeling like 24C, 13.3C nights, an extraordinarily high 165.8mm across nearly 15 days and 77 percent humidity.
KatoombaFebruaryRegular · February · 1 month ago · Read more on Tripadvisor ↗
Katoomba-forum threads comparing conditions to Sydney describe the Blue Mountains as reliably cooler by a real margin, posters calling a ten-degree difference from the city entirely plausible given the elevation. Regulars call layers standing advice regardless of season, mornings often properly brisk even when the afternoon turns pleasant. Posters describe the Three Sisters and Echo Point as worth visiting regardless of cloud cover, mist through the valley part of the experience rather than a disappointment. Regulars call the tracks around Katoomba Falls and the Prince Henry Cliff Walk both manageable this time of year, neither requiring serious gear. Posters recommend checking the Bureau of Meteorology directly rather than a generic app, mountain weather shifting faster than lowland forecasts. Regulars call the reduced crowds compared with summer a genuine upside for the lookouts. The record: 18.3C days feeling like 17C, 9.2C nights, 86.8mm across over 9 days and 78 percent humidity.
KatoombaAprilRegular · April · 1 month ago · Read more on Tripadvisor ↗
Katoomba-forum threads on June conditions describe this as genuinely early winter, daytime highs typically running comfortably in the low teens Celsius while mornings drop close to freezing on a colder stretch. Posters call fog a real feature this time of year, worth building extra time into any lookout-focused plan in case visibility is poor first thing. Regulars describe June through August as the quieter, sharper season locally, the summer haze gone and views often at their clearest despite the cold. Posters call the waterfalls genuinely fuller after winter systems, a real upside for anyone prioritizing scenery over comfort. Regulars recommend real layers regardless of how the morning starts, a cold snap capable of pushing overnight readings close to zero. Posters recommend flexible plans if a wetter stretch turns trails muddy for bushwalking. The record: 10.4C days feeling like 7C, 3.4C nights, a low 81 percent humidity and 7.5 hours of sun.
KatoombaJuneRegular · June · 1 month ago · Read more on tripadvisor.com.au ↗
Katoomba-forum threads on January weather are consistent it can turn genuinely hot, occasionally touching 30C, though posters are equally consistent this is generally milder than the heatwaves Sydney experiences the same week, roughly ten degrees cooler on an average day thanks to the elevation. That said, several visitors report the opposite surprise - a properly cool day in the middle of summer when cloud and wind roll through the escarpment, catching short-sleeved day-trippers off guard. School holidays run through January, and posters flag the Three Sisters lookout and Scenic World as genuinely crowded regardless of the weather. Regulars recommend checking a same-day forecast rather than assuming Sydney's conditions will match, since the two can diverge sharply within an hour's drive. The record: 25.2C days feeling like 26C, 14.3C nights, a notably high 162mm across 17.2 days, 77 percent humidity and 10.1 hours of sun.
EchoPointJanuaryRegular · January · 1 month ago · Read more on Tripadvisor ↗

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Katoomba climate normals — September

Daytime high16°C / 60°F🙂 cool
Nighttime low6°C / 42°F
Feels like (high)13°C / 55°F
Rainfall62 mm / 2.5 in🌦 some rain
Rainy days8 days
Humidity68%💧 humid
Dew point3°C / 37°F
Sunshine9.8 h/day
Daylight11.9 h
Wind16 km/h / 10 mph
Snowfall0.4 cm / 0.2 in
Air quality (US AQI)30🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Katoomba in September

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusySpring break in Australia, school holidays in 2 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Katoomba's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherKatoomba's weather doesn't swing hard through the year — comfort stays fairly steady in every month.

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What's on in Katoomba in September

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Nature

    Waratahs and heath in flower

    15 Sep – 15 Nov · usuallyWildflowers & blooms

    Waratahs come out along the cliff-top tracks in spring, with the heath and boronia around them. It is the best walking window of the year, before the summer heat and the fire bans.

What's on around the world in September →

Nearby, and something's on

Within 300 km of Katoomba — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Katoomba?

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Katoomba in September — FAQ

Is September a good time to visit Katoomba?
September in Katoomba: cool, a little rain, with clean air — an excellent time to visit. It ranks #3 of 12 months for Katoomba on SeasonMap's comfort score (88/100).
What is the weather like in Katoomba in September?
In September, Katoomba averages a daily high of 15.8°C and a low of 5.8°C, with about 62.3 mm of rain over roughly 8.2 rainy days.
What is the air quality in Katoomba in September?
Katoomba has a mean US Air Quality Index of about 30 in September.

Within 300 km: Sydney's Humpback migration around 15 May – 15 Nov, and Canberra's Floriade on 12 Sep – 11 Oct.