Is Monkey Mia t-shirt weather in winter?
Yes, by day22 to 23°C through winter. The nights drop to 13.
Yes, in the day. Take a jumper for the evening. Shark Bay averages 22°C in July and 23°C in June and August — noticeably warmer than Perth, which sits at 18°C over the same months. That is the whole reason people drive north in winter. The catch is the nights: minimums drop to 13°C, and it is exposed country with little shelter. The water is cold enough that most people are not swimming. Rain is negligible — Denham gets 2 to 7mm a month from November to January.
Checked on 6 October 2026.
This is the question people ask when they are in Perth in July and wondering whether driving north is worth it. The short answer is that it is about four degrees warmer, which does not sound like much and feels like a lot.
Shark Bay month by month
| Month | Day | Night | Rain | Swimming? |
|---|---|---|---|---|
| January | 31°C | 22°C | 7mm | Yes — and very hot on land |
| February | 32°C | 23°C | 16mm | Yes — the warmest month |
| March | 31°C | 22°C | 14mm | Yes |
| April | 29°C | 20°C | 14mm | Yes — and the best all-round month |
| May | 26°C | 16°C | 36mm | Bracing |
| June | 23°C | 14°C | 54mm | Cold |
| July | 22°C | 13°C | 39mm | Cold |
| August | 23°C | 13°C | 22mm | Cold |
| September | 24°C | 15°C | 8mm | Bracing |
| October | 26°C | 17°C | 6mm | Yes |
| November | 28°C | 19°C | 3mm | Yes |
| December | 29°C | 20°C | 2mm | Yes |
Bureau of Meteorology long-term monthly averages for Denham, from 34 years of records. Perth over the same winter months averages around 18°C.
What that means in practice
- Day: t-shirt weather.22 to 23°C with very little cloud through the winter months.
- Evening: a layer.13°C and exposed. The wind off the bay makes it feel cooler than the number.
- Water: cold in winter.Fine for the dolphin encounter, which is standing in the shallows, less so for a long swim.
- Rain: barely a factor.June is the wettest month at 54mm, which is still less than Hobart gets in a dry month.
- Flies: fewer in winterwhich is a real benefit that nobody mentions.
Does it affect the dolphins?
No. The wild bottlenose dolphins come into the shallows at Monkey Mia most mornings year round, managed by Parks and Wildlife rangers. Winter is as good as summer for seeing them — and the beach is far emptier. There is more on what the encounter actually is on our is Monkey Mia worth visiting page.
The trip north
| Trip | Length | Where you sleep | From |
|---|---|---|---|
| 4 Day Perth to Monkey Mia | 4 days, 3 nights | 3 nights in private rooms with ensuites — Kalbarri Edge Resort, RAC Monkey Mia Dolphin Resort on the beach in Shark Bay, then Hospitality Geraldton Motel. | $1299 |
| 6 Day Perth to Exmouth | 6 days, 5 nights | 5 nights, with a private ensuite room or a backpacker dorm at each stop — Kalbarri, RAC Monkey Mia Resort, Ningaloo Coral Bay, then two nights at the Potshot Hotel Resort in Exmouth. Private room upgrades are available. | $1449 |
| 7 Day Perth to Exmouth & Return | 7 days, 6 nights | 6 nights, private ensuite rooms or backpacker dorms at each stop — Kalbarri, RAC Monkey Mia Resort, Ningaloo Coral Bay, two nights at the Potshot Hotel Resort in Exmouth, then Geraldton. Upgrades are available. | $1699 |
The four day trip stays in private rooms with ensuites, including a night at the dolphin resort on the beach itself.
If you are going further north
It keeps getting warmer. Exmouth averages 38°C at its warmest, so in winter Ningaloo is comfortable rather than brutal — and the whale sharks are on the reef roughly March to August, which makes the cooler months the better ones to go all the way up. See our day trips from Exmouth page.
Where this comes from. Temperatures and rainfall are Bureau of Meteorology long-term monthly averages for Denham, from 34 years of records, and Perth Airport for the comparison. The ranger-managed dolphin feeding is the published position of the WA Parks and Wildlife Service. Trip details and prices are each trip's own, and update on their own.