March 2026 Climate Forecast Discussion for the period Apr-Jun through Jul-Sep 2026
**Note: ** The CCSR/IRI seasonal forecasts of precipitation and temperature issued this month are based on an objective calibration procedure that combines the output from four models: NCEP-CFSv2, CanSIPS-IC4, COLA-RSMAS-CESM1, and NASA-GEOSS2S-2. The climatological base period for normal is 1991-2020. The SST anomalies cited below refer to the OISST.v2.1 SST data set. Starting from June 2024, the observed climatology used to compute the dry mask was updated to 1991-2020, and the criterion modified to mask points where 10% of the training sample (i.e. 3 or more years) received less than or equal to 1 mm over a 3-month season.
During February 2026, sea surface temperature (SST) anomalies weakened further and settled within the ENSO-neutral category across the central-eastern equatorial Pacific Ocean, with the monthly Niño 3.4 index at −0.20 °C. Weekly averaged SST anomalies in the Niño 3.4 region were −0.0 °C for the week centered on March 11, 2026, indicating the persistence of values within the ENSO-neutral range. The early March CPC ENSO forecast, maintained a “La Nina Advisory”, but also issue “El Nino Watch”, with a transition to ENSO-neutral expected in the next month, and with El Niño likely to emerge in boreal summer. (It is important to note that the ENSO monitoring and prediction issued by CPC is now based on the relative Niño 3.4 index.) The Indian Ocean Dipole (IOD) index is currently weakly positive, with a DMI value of +0.45 for the month of February 2026. The North Atlantic Ocean continues to exhibit slightly warm SST anomalies. The Pacific Decadal Oscillation (PDO) Index recorded a value of -1.01 °C in February 2026.
The CCSR/IRI objective Multi-Model Probability Precipitation Forecast for April–June (AMJ) 2026 indicates elevated odds of above-normal precipitation (green/blue shading) across parts of South America, South Africa, and Southwest South Asia. In May–July (MJJ) and June-August (JJA), wetter-than-normal conditions are expected in the central Amazon region and South Africa. From MJJ to July–September (JAS), forecasts show a slightly elevated probability of above-normal precipitation over the Sahel region. The outlook also indicates increased likelihoods of below-normal precipitation (yellow to brown shading) from Central America to northern South America, as well as in the Maritime Continent region and Australia during the forecast period (AMJ to JAS). Many of these gradual shifts in probabilities are consistent with the expected transition from La Niña to ENSO-neutral conditions, followed by a further transition to El Niño during the early boreal summer season.
The temperature forecasts indicate that above-normal temperatures (red shading) are highly probable in most seasons across much of North America, northern and central Eurasia, the Middle East, and large portions of Africa and South America. In May–Jul and Jun–Aug, areas of below-normal temperatures (blue shading) are notable in parts of northern Australia.
