The sea-surface temperature (SST) anomaly map for April shows near-average SSTs across nearly the entire tropical Pacific. A small area of cool anomalies hugs the South American coastline and warm anomalies continue across most of the Maritime Continent region. The eastern equatorial Pacific has cooled compared to April but elsewhere anomalies remain similar.

Baseline period 1961–1990. Index March April Temperature change NINO3 +0.3 +0.1 0.2 °C cooler NINO3.4 +0.1 +0.1 no change NINO4  0.0  0.0 no change

SST anomalies have cooled in the eastern equatorial Pacific when compared to two weeks ago. The map for the week ending 5 May shows negative SST anomalies are present along the equator between the South American coast and 130°W. Elsewhere along the equator SSTs are near average with above warm anomalies in the far western Pacific and across the south of the Pacific Basin, poleward of the tropics. Warm anomalies also remain around much of the Australian coastline.

Baseline period 1961–1990. Index Previous Current Temperature change (2 weeks) NINO3 +0.2 −0.1 0.3 °C cooler NINO3.4 +0.1 +0.1 no change NINO4  0.0  0.0 no change

An animation of recent SST changes | Weekly data graph | Map of NINO regions

Compared to two weeks ago, the sub-surface map for the 5 days ending 5 May shows cool anomalies in the subsurface of the eastern Pacific have strengthened; water more than 1 °C cooler than average is present between 50 and 250 m deep across nearly all of the equatorial Pacific, reaching more than 3 °C cooler than average east of the Date Line. Warm anomalies are still present in the far western equatorial Pacific sub-surface.

Animation of recent sub-surface changes | Archive of sub-surface temperature charts

The Southern Oscillation Index (SOI) has continued to drop over the last two weeks. The latest 30-day SOI value to 5 May is −3.6.

Sustained positive values of the SOI above +8 may indicate a La Niña event, while sustained negative values below −8 may indicate an El Niño event. Values of between about +8 and −8 generally indicate neutral conditions.

Monthly_graph | SOI table | SOI text

Trade winds have strengthened across the western tropical Pacific during the past two weeks. The anomaly map for the 5 days ending 5 May shows trade winds are stronger than average across the far western tropical Pacific and near average elsewhere.

During La Niña events, there is a sustained strengthening of the trade winds across much of the tropical Pacific, while during El Niño events there is a sustained weakening of the trade winds.

Cloudiness near the Date Line has been below average during the past two weeks.

Cloudiness along the equator, near the Date Line, is an important indicator of ENSO conditions, as it typically increases (negative OLR anomalies) near and to the east of the Date Line during an El Niño event and decreases (positive OLR anomalies) during a La Niña event.

International climate models surveyed by the Bureau indicate that SSTs in the equatorial Pacific Ocean are likely to remain neutral at least until the southern hemisphere spring.

The Indian Ocean Dipole (IOD) is currently neutral, with the latest IOD index value at +0.2 °C for the week ending 5 May. Current model outlooks indicate the IOD will remain on the cool side of neutral into the southern hemisphere winter. However, three of the five models surveyed indicate the possibility of a negative IOD heading into the southern spring. A negative IOD during spring increases the chances of above normal rainfall over southern Australia.

IOD time series IOD map IOD forecasts DMI values