The Mackay Wet Season That Was: Heatwaves, Floods, and Cyclone Koji (2025–2026)

Author: Chris Nitsopoulos

Posted on: Tuesday, June 2nd, 2026, 8:42:34 AM

 

If there is one word to describe Mackay’s 2025–2026 wet season, it’s whiplash.

 

Looking at the cumulative rainfall graphs, the region spent the first few months of the season tracking well below historical medians, pointing toward a very dry summer. But the tropics always have a wild card up their sleeve. In January, the atmospheric switch flicked, bringing relentless monsoonal downpours and the devastating impacts of Tropical Cyclone Koji.

 

 

Here is the month-by-month breakdown of how the wet season played out across the Mackay region.

 

October 2025: A Thirsty Start

• Total Rainfall: 15.6 mm

 

• Highest Temperature: 35.1°C (Oct 29)

 

• Monthly Vibe: Dry, dusty, and building heat.

 

October offered practically zero relief for parched gardens. With a measly 15.6 mm of rain falling over the entire month, the region tracked well below average. The month ended with an intense heat spike, pushing the mercury up to 35.1°C on October 29 and giving locals a taste of the sweltering build-up to come.

 

 

November 2025: The Sizzling Build-Up

• Total Rainfall: 64.0 mm

 

• Highest Temperature: 38.0°C (Nov 25)

 

• Monthly Vibe: Extreme heat with teaser storms.

 

November is traditionally when the humidity starts to bite, but this year it brought genuine heatwave conditions. On November 25, the Mackay Airport recorded a scorching 38.0°C, accompanied by intense north-westerly winds. We saw a few isolated storms—most notably a 30.4 mm dumping on November 6 and 18.8 mm on November 17—but overall, the real wet season remained frustratingly out of reach. 

 

 

 

 

December 2025: A Humid Holiday

• Total Rainfall: 90.6 mm

 

• Highest Temperature: 34.8°C (Dec 23)

 

• Monthly Vibe: Late arrivals and a wet Christmas.

 

December looked like it was going to be another dry disappointment until Santa arrived. Temperatures peaked at 34.8°C on December 23, creating incredibly muggy, uncomfortable conditions. The atmosphere finally broke right on cue for the holidays, delivering over 70 mm of rain between Christmas Day and December 27, ensuring a wet and wild end to the year.

 

 

 

January 2026: The Wrath of Cyclone Koji

• Total Rainfall: 383.8 mm (Mackay Airport)

 

• Max Wind Gust: 83 km/h (Jan 11)

 

• Monthly Vibe: The atmospheric floodgates open.

 

January was the undisputed turning point of the season. After tracking below average for months, the region was slammed by Tropical Cyclone Koji.

 

Forming in the northern Coral Sea, Koji officially made landfall as a downgraded tropical low between Ayr and Bowen on January 11. However, cyclones are notorious for their trailing southern edges. Mackay was caught directly in the system's crosshairs, experiencing severe easterly wind gusts of 83 km/h on January 11, followed by an absolute deluge.

 

The airport recorded 150.2 mm in a single day on January 12, and a further 71.0 mm on January 15. The inland impacts were even more extreme. Moisture from Ex-Tropical Cyclone Koji funneled into the Pioneer River catchment, with some localized elevated areas (like Mount William) recording over 600 mm in a 48-hour window. This triggered major flash flooding, agricultural damage, and widespread power outages across the Mackay and Whitsunday regions.

 

 

 

 

February 2026: The Relentless Monsoon

• Total Rainfall: 422.4 mm

 

• Highest Daily Rain: 93.6 mm (Feb 4)

 

• Monthly Vibe: Saturated and waterlogged.

 

With the catchments already overflowing from Koji, February showed absolutely no mercy. It officially became the wettest month of the season at Mackay Airport. Persistent monsoonal flows kept the skies grey and the rain heavy. The first week of February was particularly brutal, bringing a combined 175 mm between February 4 and 6, followed by another massive 82.4 mm dump on February 17. The ground simply couldn't absorb any more water.

 

 

 

March 2026: The Final Flush

• Total Rainfall: 304.2 mm

 

• Highest Daily Rain: 99.2 mm (Mar 7)

 

• Monthly Vibe: The tail-end thrashing.

 

Just when locals thought they could hang their raincoats up, March delivered one final flush. A massive 99.2 mm downpour on March 7 reminded everyone that the tropics were still highly active. The first half of the month also saw aggressive wind gusts repeatedly topping 50–60 km/h, keeping the seas incredibly choppy before the monsoon trough finally began its retreat northward.

 

 

 

 

April 2026: The Dry-Out

• Total Rainfall: 46.4 mm

 

• Monthly Vibe: The return to paradise.

 

By April, the atmospheric tap finally turned off. Rainfall dropped off a cliff, totaling just 46.4 mm for the month. The humidity broke, the severe weather systems dissipated, and the region transitioned beautifully into the stable, mild conditions that make North Queensland winters so famous.

 

 

Season Summary: A Tale of Two Halves

The 2025–2026 wet season will be remembered for its dramatic pivot. The first three months left the region vulnerable to drought and extreme heat, while the final three months delivered over 1,100 mm of rain, driven heavily by the chaos of Cyclone Koji. It is a classic reminder of life in the tropics: the rain will always come, and when it does, it doesn't hold back.

 

 

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The Upcoming Season/s

 

The Hard Data (As of June 2026)

• Bureau of Meteorology (BOM): In their latest long-range forecast released on June 1, 2026, the BOM confirmed that while ENSO is currently neutral, Pacific sea surface temperatures are rising rapidly. They explicitly forecast an El Niño to develop this winter and are already predicting below-average rainfall and above-average daytime and nighttime temperatures for eastern Queensland.

 

• World Meteorological Organization (WMO) & NOAA: The WMO and NOAA just released updates indicating an 80% to 82% likelihood of an El Niño forming between May and July 2026, with a 96% chance it persists through the end of the year. Because subsurface ocean temperatures in the Pacific are currently tracking up to 6°C above average, climate models are warning that this is likely to be a strong—and potentially severe—El Niño event.

 

Based on these specific, current indicators, here is the realistic forecast for Mackay.

 

 

The Dry Season & Build-Up (June 2026 – November 2026)

• Accelerated Drying and Extreme Fire Risk: The BOM’s forecast for a warmer, drier winter is the biggest immediate red flag for the Mackay region. Because the relentless rains from Cyclone Koji triggered explosive vegetation growth earlier this year, a dry, hot June through August will turn that overgrowth into a massive fuel load. Bushfire risk in the Pioneer Valley and surrounding ranges will spike significantly by August and September.

 

• A Punishing Spring: With a strong El Niño firmly taking hold by September and October, the usual early, scattered thunderstorms that offer brief relief during the build-up will be heavily suppressed. Expect prolonged, dry heatwaves, relentless sun, and rapidly dropping water levels in local catchments heading into November.

 

The Wet Season (December 2026 – April 2027)

• A Late, Weak Arrival: El Niño pulls the tropical moisture pool eastward across the Pacific, away from Australia. Because of this, Mackay's wet season will likely be significantly delayed. December is expected to be intensely hot and largely dry, completely flipping the script on the holiday soaking the region received in 2025.

 

• Below-Average Rainfall: January and February are Mackay's historically wettest months, but the overarching climate driver will be actively working against sustained monsoonal flows. While localized severe storms are always a given in the tropics, the overall seasonal rainfall totals are highly likely to fall well short of historical averages.

 

• Reduced Cyclone Threat: The shifting wind shear and ocean temperatures associated with El Niño generally reduce the total number of tropical cyclones forming in the Coral Sea. While the risk is never zero, a repeat of a direct, waterlogged hit like Koji is highly unlikely this coming season.

 

 

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WHEN IS THE BEST TIME TO HOLIDAY IN THE MACKAY AREA?

 

Book a motel here and help our page :) 

 

 

Historically, the broader winter and early spring months are the clear winners, but the 2026 climate drivers add a slight complication. Here is the breakdown of exactly when to book your trip and when to steer clear.

 

🏆 The Absolute Sweet Spot: June & July

If you are planning a trip for this year, right now through July is your best bet.

• The Historical Data: According to your chart, these months offer the most comfortable daytime temperatures, peaking at a mild 23.3°C in June and 22.8°C in July. Rainfall drops off significantly compared to the wet season, averaging just 57.6 mm and 39.5 mm respectively.

 

• The El Niño Factor: Under the current developing El Niño, these months will be exceptionally clear, crisp, and dry. Crucially, visiting in June or July means you get to enjoy the region before the massive vegetation load left over from Cyclone Koji dries out completely and turns into a severe bushfire hazard late in the season.

 

🥈 The Historical Favourite (With a 2026 Catch): August & September

Usually, these two months are the absolute peak of Mackay's tourism season, but this year comes with a warning label.

 

• The Historical Data: The stats show this is the driest and sunniest part of the year. September has the lowest mean rainfall of the year at just 23.0 mm, while August boasts the highest number of completely clear days (14.8 days). The weather is objectively beautiful.

 

• The El Niño Factor: Because the El Niño will suppress winter rainfall, by the time August and September roll around in 2026, the region will be a tinderbox. While the skies will be clear of rain clouds, there is a very high likelihood that an occasional day will be hazy with bushfire smoke towards the end of September, which could impact outdoor activities, hiking in the Eungella hinterland, and general sightseeing.

 

🚫 The "Avoid" Window: October through April

 

Unless you are specifically chasing extreme weather or don't mind sweating through your shirt in five minutes, you should avoid the build-up and the wet season.

 

• The Sizzling Build-Up (Oct - Nov): The chart shows temperatures climbing rapidly toward the 30°C mark, but El Niño will supercharge this. Expect prolonged, brutal heatwaves with little rainfall relief.

 

• The Wet Season (Dec - Apr): Historically, this is when Mackay gets absolutely drenched. January (310.5 mm), February (332.5 mm), and March (249.6 mm) account for the vast majority of the region's annual rain. Furthermore, January averages 15.3 cloudy days out of the month. Even though El Niño is expected to suppress the overall rainfall totals for the upcoming 2026/2027 wet season, the humidity, heat, and risk of localized severe storms still make this a highly uncomfortable time for a holiday.

 

 

The Verdict: Pack your bags for June or July and into August. You will get the historical benefit of cool, dry days, and completely dodge both the tropical deluge of the wet season and the heightened El Niño fire risks of the late dry season.

 

 

 

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Previous Summaries

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Cairns 25/26 season