Melbourne weather in September

Regulars back their reputation for wild swings with a specific example rather than a general claim: one October saw 16C, then 26C the very next day, then back down to 16C the day after that - three days, three different seasons in effect. Our row backs a mild average across that range, 21C over 10.3C nights, with 78mm of rain across 9.9 days and a real 21.7 kph wind. Regulars describe the realistic range across the month as anywhere from 14 to 35C, most likely landing in the low 20s, with layering the only sensible way to handle a day that can genuinely go either way. The sea sits at a cool 15.8C. The record: humidity 70 percent, 9.7 hours of sun and one of the cleanest air readings in this project, AQI 32.

Regulars are direct that late spring here means genuine swing rather than a single number: a warm afternoon can meet a cold front and drop ten degrees in half an hour, with cool mornings, mild-to-warm afternoons and a cooling evening all inside the same day. Our row backs the range, 22.9C over 12.3C nights, with 68.4mm of rain across 9.1 days and a real 20.8 kph wind - regulars describe the rain itself as more heavy passing showers than steady drizzle. The standard packing list follows directly from the swing: shorts and a t-shirt for the warm stretch, a long-sleeved layer and a cardigan or light jacket for the cooler hours either side. The sea holds 18.2C. The record: humidity 69 percent, 10.4 hours of sun and AQI 32.

Locals will tell you the four-seasons-in-a-day line is more legend than forecast - by their own count it happens two or three days a year - but they will also tell you December is genuinely changeable, running mid-twenties to low thirties with the odd heatwave near forty and cool stormy spells that often follow one. Our row averages that at 25.6C over 14C with 55.4mm across 7.2 days. The night is the part people underpack for: fourteen degrees, feeling thirteen in a 21.2 kph wind, after an afternoon in the high twenties. The bay reaches 19.8C. The record: humidity 66 percent, 11.4 hours of sun inside 14.7 of daylight, and AQI 30.

February is Melbourne's hottest month and its most volatile. Regulars give the local rule bluntly: it can be 40C at two in the afternoon and 26C at half past, and February holds both some of the city's hottest days on record, into the mid-40s, and some of its wettest, with more than 80mm in 24 hours. They are divided on the four-seasons-in-one-day slogan, some calling it more myth than reality, but agreed on the consequence, which is layers and a flexible plan. The geography is the explanation - a hot dry continent to the north and Antarctica as the nearest southern neighbour. The record: 26.7C days, 15.5C nights, 3.8 precipitation days carrying 25.2mm and a 21.2C sea.