Exmouth weather in September

September is the month Ningaloo changes hands. Whale shark swims run April to August; humpback swims run September to November - so this is the first month of one season and just past the last of the other, and which animal you came for decides whether September is early or late. The weather side is straightforward: our row gives 26.6C over 19C, 1.8mm of rain across half a precipitation day, and 57 percent humidity, which is as close to guaranteed as this collection gets. The variable is water, not sky - regulars warn the outer reef can turn choppy enough to move or cancel a tour, and our 25.4 kph average is why. Campsites like Osprey fill up, so book online ahead. The record: 11 hours of sun, a 23C sea and AQI 30.

Regulars are specific this technically counts as wet season here, though some years bring no real rain at all, the total for the month entirely dependent on whether a cyclone or low-pressure system happens to pass through - if one does, most of that rain falls in a short, concentrated burst. Our row backs that hot, genuinely dry read, 31.8C reading as a scorching 35C, over 25.1C nights feeling 26C, with rain light at 11.3mm across 1.2 days and humidity at 67 percent. Regulars are consistent a cyclone is possible but genuinely unlucky to encounter, April and May instead named as the better overall window once things cool down with almost no wind for clearer snorkeling water. The sea sits at a warm 26.3C. The record: 12.2 hours of sun, a 28 kph wind and AQI 46.

December here is hot rather than extreme by local standards, and regulars are candid about the trade-off: no lines at the shops, quiet roads, warm water, but wind strong enough on some days that people are actively told to skip the reef trip because it ruins the beach and snorkelling conditions. Cyclone season technically starts mid-December and runs to April, though the actual risk in any given week stays small. Our row backs the heat and the wind both - 31.3C reading as 34C, and a real 27.8 kph average - with rain essentially absent at 1.5mm across half a day. The sea is 25.3C, comfortably swimmable whatever the wind is doing on land. The record: humidity 64 percent, 12.5 hours of sun and AQI 34.

May sits inside the whale shark season, which the Exmouth visitor centre gives as April to July, and people report swimming with them as early as the first of the month. The geographic detail is the useful one: the sharks show up around Coral Bay to the south early in the season and work north towards Exmouth a little later, so a May trip may be better based down the coast than up here. May is also when the mantas arrive, and they stay through to November. Our row is about as easy as a month gets - 27.5C over 21.2C, 35.9mm across 1.7 precipitation days, 58 percent humidity and a 24.4C sea. The record: 9.8 hours of sun, a 21.2 kph wind and AQI 24.

November at Ningaloo is defined by what has already finished. The whale sharks are gone - their season runs roughly March or April to September, and regulars are blunt that November is far too late - and the humpbacks with them. What November has instead is turtle breeding and nesting, which starts now. It is also the opening of the cyclone season, which really belongs to December through March but can already curtail things, while the heat of high summer has not properly arrived. Wind is a year-round feature here, and the peninsula's answer is to cross to the sheltered east side of town when the west is blowing. The record: 29.1C days, 21.5C nights, 0.5 precipitation days, 12.1 hours of sun, a 25C sea and a 27.5 kph wind.