Updated 2026-09-25

Solar & Daylight Data

Daylight & Orientation: Sydney, Australia

Monthly and seasonal sunlight on each wall orientation and the roof in Sydney, Australia, with cloud cover.

On this page

Last updated September 25, 2026 · Location: GeoNames point -33.8678, 151.2073 ([GeoNames AU dump](https://download.geonames.org/export/dump/AU.zip), CC BY 4.0, ID 2147714); time zone Australia/Sydney from the same GeoNames record. Sun positions, sunrise and sunset calculated by Harth with [NOAA's solar calculator equations](https://gml.noaa.gov/grad/solcalc/calcdetails.html), including standard atmospheric refraction, for a sea-level horizon. Sunlight, cloud and air temperature: [NASA POWER climatology](https://power.larc.nasa.gov/docs/services/api/temporal/climatology/) monthly means for 2001–2020 at this point (API v2.10.0, retrieved 2026-09-25).

Direct answer

A north-facing wall in Sydney receives 1,185 kWh/m² of sunlight a year and 347 kWh/m² in June–August, the most winter sun of any wall. In December–February the east and west walls take the most, 311 kWh/m² each, while a south wall gets 516 kWh/m² a year. A flat roof receives 1,696 kWh/m² a year. Cloud cover averages 55%, lowest in August and highest in February. East and west walls each receive 982 kWh/m² a year, 32% of it in December–February. In August, the clearest month, a flat roof receives 3.7 kWh/m² a day and the clearness index reaches 0.59. North-east and north-west walls receive 1,159 and 1,158 kWh/m² a year; south-east and south-west walls 686.

Content and cited inputs reviewed by Harth team · Published 2026-08-26 · Updated 2026-09-25.

How much sunlight does each Sydney facade get, month by month?

Total solar energy reaching a square metre of wall or flat roof in each month, in kWh/m², from NASA POWER all-sky averages for 2001–2020.

MonthRoofNorthEastSouthWestCloud cover
January201751116911159%
February1597789498961%
March14910086448659%
April11510969336954%
May9211958255852%
June7110045214558%
July8612055235549%
August11412670307046%
September14511486378547%
October176941004910055%
November186761036210361%
December203731117311160%

Yearly and seasonal sunlight by orientation in Sydney

SurfaceYear (kWh/m²)June–AugustDecember–FebruaryShare of year in December–February
Roof1,69627056333%
North1,18534722519%
North-east1,15927828425%
East98217031132%
South-east6868626038%
South5167419137%
South-west6868626038%
West98217031132%
North-west1,15827828425%

How clear the sky is over Sydney

Cloud cover averages 55% over the year, from 46% in August to 61% in February. The clearness index — the share of sunlight above the atmosphere that reaches the ground — peaks at 0.59 in August. A flat roof receives 1,696 kWh/m² a year, 3.7 kWh/m² a day in August.

Choosing orientations in Sydney

For winter sun, the north facade is the one to glaze: it collects 347 kWh/m² over June–August, against 74 for the south facade. In December–February the east and west facades take the most sun, 311 kWh/m² each, so large glazing there needs external shading or low-g glass. The south facade gets the steadiest, mostly diffuse light — 516 kWh/m² a year — which suits studios and deep-plan rooms that need daylight without glare.

How these figures were calculated

NASA POWER gives mean daily global and diffuse sunlight on a horizontal surface for each month. Harth split each day into 10-minute steps with the Collares-Pereira & Rabl and Liu & Jordan profiles, projected each step onto vertical walls with an isotropic sky and ground reflectance of 0.2, and multiplied by the days in the month. East and west come out equal because the averages are symmetric about solar noon; on a real site, afternoon cloud, neighbouring buildings and trees change the split.

Sources and method

Location: GeoNames point -33.8678, 151.2073 (GeoNames AU dump, CC BY 4.0, ID 2147714); time zone Australia/Sydney from the same GeoNames record. Sun positions, sunrise and sunset calculated by Harth with NOAA's solar calculator equations, including standard atmospheric refraction, for a sea-level horizon. Sunlight, cloud and air temperature: NASA POWER climatology monthly means for 2001–2020 at this point (API v2.10.0, retrieved 2026-09-25).

Monthly sunlight on the roof and on north, east, south and west walls for Sydney, Australia
Monthly sunlight on each surface for Sydney, Australia, plotted from the table above.
Mean cloud cover by month for Sydney, Australia
Cloud cover by month for Sydney, Australia, plotted from the table above.

Frequently asked questions

Which way should a house face in Sydney for winter sun?

Face the main living spaces north. In Sydney a north-facing wall receives 347 kWh/m² of sunlight over June–August, compared with 170 for east or west and 74 for south.

How much sun does a west-facing wall get in Sydney in summer?

About 311 kWh/m² over December–February, 32% of its yearly 982 kWh/m², arriving as low afternoon sun that overhangs do not stop.

How cloudy is Sydney?

NASA POWER satellite records for 2001–2020 put Sydney's mean cloud cover at 55%, from 46% in August to 61% in February.

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