Parts of the Top End and Far North Queensland are now in a period where shadows disappear beneath your feet. 

As the springtime begins to venture south of the equator, the sun will see itself in the southern half of the sky for the first time in a while anywhere north of about 13ºS from October 27th until early next year. 

This phenomenon has been coined 'Lahaina noon', originating from Hawaii, where the sun appears directly overhead exactly two times per year. For them, being in the northern hemisphere, this happens once in May, then again in July.  

In fact, Lahaina noon occurs anywhere in the tropics, or in Australia's case, north of the Tropic of Capricorn, two times between late October and mid-February. 

What better way to visualise this than with satellite imagery & tropical cumulus clouds? Of course, from the ground, the cloud shadows will be seen – but from satellite imagery, it's almost as if they weren't there.

Figure 1: Tropical cumulus clouds over Far North Queensland around the Lockhart River at approximately solar noon, with invisible shadows (top) and about 3 hours after solar noon, with visible shadows (bottom) on October 27th. Picture taken using Himawari satellite imagery. 

Figure 2: Tropical cumulus clouds over the NT's Top End at approximately solar noon, with invisible shadows (top) and about 3 hours after solar noon, with visible shadows (bottom) on October 27th. Picture taken using Himawari satellite imagery. 

Thankfully, since the monsoon season is yet to start in November, generally dry conditions with some room for sunlight to peek through are expected, at least until the end of the month.

Take a look at the map. The 90º line shows where Lahaina noon is occurring on October 28th, and the Tropic of Capricorn is the southernmost extent of Lahaina noon. Each successive horizontal line shows the separations of 10º of inclination of the maximum sun angle in the sky, where the horizon is 0º and directly overhead is 90º. 

Figure 3: Australian map showing the highest sun inclination in the sky at about solar noon in degrees (º) above the horizon on October 28th, 2023. The sun appears in the southern half of the sky to the north of the 90º line (NOAA Solar calculator, 2023). 

As the sun's peak tracks south, summer & the monsoon season approach. Cairns can expect its Lahaina noon on November 10th, Broome on November 13th, and Rockhampton on December 18th – well into the 'wet season' where disappearing shadows may disappear for other reasons – namely, cloud cover.  

The southernmost Lahaina noon should occur at the Tropic of Capricorn on December 22nd, 2023 – the summer solstice. At this point, even the southern tip of Tasmania will see the sun at a 70º elevation to the north, and far North Queensland will see the sun at a 78º elevation to the south. 

Until then, if you happen to be within the tropical belt, you can use the sun calculator here to see what time, and date, the sun will be directly above you.