Following on from the posting about seasons, a good 'indicator' of summer in much of Australia is when the Hyacinth Orchid flowers.
The local species, Dipodium roseum, is in full flower today in the bushland between Killara and St Ives. If you haven't seen a Hyacinth Orchid before, look for a tall flowering stalk with 20-40 generally pink blotched flowers. It has no leaf and in fact gets all its food from organic matter in the soil via associated fungi.
So although it is bitterly cold today, 'summer' has perhaps started. I'm sure correspondent Rick Kemp won't mind me mentioning that in his scheme the 'warm and brightly lit season' (summer) begins on 15 November. Which is conveniently close to when the first Hyacinth Orchid flowers open in most years.