One of the principles I return to constantly is seasonality. In Japan, the concept of shun — eating ingredients at their peak season — is fundamental to the cuisine. A fish at its seasonal best has a flavour and texture that the same fish at a different time of year simply cannot match. Australia’s waters offer a remarkable diversity of seafood, and understanding when each species is at its finest will transform your sushi and sashimi.

This guide covers the broad seasonal patterns for the fish most relevant to sushi lovers in Australia. Keep in mind that seasons shift slightly depending on where you are — what peaks in January in Sydney might peak in February in Tasmania — and that weather patterns, water temperatures, and other factors create year-to-year variation.

Summer (December - February)

Summer is peak season for many of Australia’s prized sushi fish, which works out well since the hot weather naturally steers appetites toward lighter, cooler dishes like sashimi.

Hiramasa kingfish is at its best through the summer months. The fish are actively feeding and carrying good fat content. Wild-caught hiramasa from South Australia is particularly outstanding — the flesh is firm, clean, and subtly sweet with a richness that pairs beautifully with a touch of yuzu and salt.

Yellowfin tuna runs along the east coast through summer, and fresh, locally caught yellowfin has a vibrancy that imported product rarely matches. The flesh is a deep, ruby red and the flavour is clean and minerally.

Prawns — particularly school prawns and banana prawns — are abundant and sweet. For sushi, look for the freshest raw prawns you can find. Eaten as amaebi-style nigiri, summer prawns have a creamy sweetness that is hard to beat.

Sea urchin (uni) from Tasmania is available through summer and is world-class. The lobes are sweet, briny, and creamy, with a flavour that tastes like the ocean distilled. It is expensive but worth seeking out at least once.

Autumn (March - May)

As the water cools, some fish begin to fatten in preparation for winter, which can produce exceptional eating quality.

Snapper hits its stride in autumn. The flesh firms up and develops a sweet, delicate flavour that makes it ideal for sashimi. A thin slice of fresh snapper with a squeeze of sudachi citrus is one of the simplest and most satisfying things you can eat.

Bonito (skipjack tuna) is traditionally associated with the first catch of autumn in Japan, and Australian bonito follows a similar pattern. The flesh is darker and more robustly flavoured than other tuna species. It is excellent seared on the outside and raw within — the preparation known as tataki.

Blue swimmer crab is plentiful in autumn. While not a traditional sushi ingredient, the sweet meat makes excellent temaki (hand rolls) and works beautifully mixed with avocado and a touch of ponzu.

Squid is at peak quality in autumn, with firm, sweet flesh that slices beautifully for sashimi. Score the surface in a fine crosshatch pattern to tenderise it and improve the texture.

Winter (June - August)

Winter brings colder waters and fattier fish, which is ideal for rich sushi and sashimi preparations.

Southern bluefin tuna is a winter highlight. The fish feed heavily as the water cools, and the belly portions develop extraordinary fat marbling. The difference between winter and summer bluefin is substantial, and the best toro I have ever eaten in Australia has always been in the cooler months.

Blue-eye trevalla is a deep-water species that is available year-round but is particularly good in winter. The flesh is white, moist, and mildly flavoured — excellent for those who prefer a subtler sashimi experience.

Oysters are at their plumpest and most flavourful through winter, particularly Sydney rock oysters and Pacific oysters from Tasmania. While not sashimi in the traditional sense, a fresh oyster with a drop of ponzu bridges the same culinary territory.

Abalone from Tasmania and South Australia is a luxury item that peaks in winter. The texture is firm and slightly chewy, the flavour sweet and intensely oceanic. Thinly sliced and served raw, it is an extraordinary experience.

Spring (September - November)

Spring is a transitional season, with some winter species fading and summer species beginning to appear.

Flathead is underrated as a sashimi fish but deserves more attention, particularly in spring when the flesh is clean and firm. The flavour is mild and sweet, sitting somewhere between snapper and whiting.

Barramundi from northern waters is available year-round but the spring catch often has a particularly good texture. It is a versatile sushi fish that works well as both nigiri and sashimi, with a buttery quality that appeals to those who find some white fish too lean.

Scallops from Tasmania begin their peak season in spring and continue through summer. The natural sweetness of a fresh, raw scallop needs almost no accompaniment — perhaps just a drop of good soy sauce.

Eating With the Seasons

The practical benefit of eating seasonally is that you get better-tasting fish for the same money. A kingfish in January is fattier, more flavourful, and more readily available than a kingfish in July. Supply and demand work in your favour when you eat what is naturally abundant.

But there is also something satisfying about the rhythm itself. Anticipating the first bonito of autumn or the winter bluefin creates a relationship with the food calendar that makes each meal more meaningful. It connects you to the ocean, the weather, and the natural cycles that sustain everything on your plate.

Some forward-thinking fish suppliers and restaurants are now using data tools to track seasonal availability patterns more precisely. A handful of AI strategy support firms have been working with Australian food businesses to build predictive models for fish sourcing — matching historical catch data with weather patterns and market pricing. It is early days, but the idea of data-informed seasonality appeals to me.

Ask your fishmonger what is best right now. They will tell you, and it will almost always be more interesting than defaulting to salmon again.