Spring 2025 Climate Outlook for Australia
1. Indian Ocean Dipole (IOD) – Wet Bias Emerging
The Bureau of Meteorology foresees a shift toward a negative IOD from August to November — a pattern typically linked with above-average rainfall in central and eastern Australia, especially inland areas. Experts estimate a 70–80% chance of above-median rainfall across much of central/eastern Australia this spring. Expect daytime temps to be cooler than average in some interior and eastern zones, while nights trend warmer from cloud cover and moisture.
2. ENSO – Neutral, Leaning La Niña
Models from the Bureau and independent analysis continue to lean toward an ENSO-neutral or weak La Niña scenario through spring 2025. The latest Niño 3.4 SST anomalies suggest a neutral forecast for July to September, with a modest tilt toward La Niña later in the year.
3. Southern Annular Mode (SAM) – Cooling from Positive
SAM recently peaked at its most positive value in two years — favoring higher pressure over southeastern Australia, which suppressed frontal rainfall during winter. However, the index has been drifting back toward neutral, making spring weather a bit more open to frontal influences again.
4. Surface Patterns – Warm Seas Fueling Rain Potential
Sea Surface Temperatures (SSTs) remain anomalously warm around much of Australia, increasing moisture availability for storm systems, especially across eastern and northern regions.
What This Means for Spring Weather
Driver Impact: Negative IOD boosts rainfall for eastern and central Australia, especially inland areas. Neutral/weak La Niña slight wet bias, but not at La Niña’s reliable intensity. SAM trending neutral frontal systems more able to reach southern regions. Warm SSTs Increased moisture for storms — particularly useful if fronts return.
Forecast Notes:
Expect above-average rainfall in eastern and central parts, with higher odds of heavy falls from thunderstorms or frontal activity.
Southern WA and southwest Tas may remain relatively dry.
Overall, a mix of rain chances, warmer nights, and cooler daytime highs.
Frost risk likely diminishes—but keep an eye on those late-stage dry spells.
Spring Forecast 2025: Moist Mornings Ahead
Spring is shaping up to offer a handshake rather than a slap — easing frost, boosting rain chances, and keeping things unpredictable.
The Indian Ocean Dipole is cracking into negative territory. Translation? Rain return to central and eastern Australia.
La Niña is out — neutral ENSO takes the wheel for now, with a soft leaning toward wetter La Niña patterns later.
The SAM is cooling off from its winter peak, opening up the door to more frontal systems in the south.
Meanwhile, warm coastal oceans are primed to feed moisture-rich systems whenever they arrive.
What to expect: a wetter-than-average spring for large parts of the country, warmer nights, cooler highs, and fewer frost scares than winter. Stick close to the frost and rainfall maps — this is shaping up to be a season that rewards staying in touch with the data.