In the southern hemisphere, well at least Australia/NZ not sure about Africa and South America, the official start of the season is the June 1, September 1, December 1 and March 1. However the solstice cannot be the middle of the season as the ground takes longer to warm/cool than the air. That is why the hottest part of the day is after the sun reaches the zenith (midday but probably later due to DLS) and begins to go down in the sky. It snowed here last Monday but melted almost as soon as it hit the ground. We had not had any frosts. We had light frosts on Wednesday and Thursday (heavier down in the valley below). May be this morning, still too dark to see. So if it snows next week (none forecast) there is more chance of it settling. July/August are our colder months but we can have snow into November.