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Seasonal Forecasts

Temperature and precipitation outlooks on seasonal (multi-month) timescales.

Forecast

Current seasonal temperature and precipitation outlook maps and discussion. Released on or about the 15th of each month.

Using the forecast maps

Use the controls above each map to choose what it shows. On the seasonal page you can pick the forecast Source, the Type (precipitation or temperature) and the date the forecast was issued. On the subseasonal page you pick the Type, then the year, month and day of issue. The map updates as soon as you change a setting. The box of buttons on the map switches between the forecast periods in that issuance: target seasons on the seasonal map, forecast periods on the subseasonal map. The title changes to match the period you pick. You can zoom with the scroll wheel or the +/– buttons and drag to move around the map. Download PNG saves the period currently shown as an image, with its title and legend.

CCSR/IRI NMME Multi-Model Probability Forecast for Precipitation for
May-June-July Issued April 2021
Probability (%) of Most Likely Category
Below Normal
40
45
50
60
70+
Normal
40+
Above Normal
40
45
50
60
70+
Dry Season (No Forecast) Equal Odds

April 2021 Climate Forecast Discussion

April 2021 Climate Forecast Discussion for May-Jul through Aug-Oct

Note: The IRI seasonal forecasts issued this month are based on the NCEP-CFSv2, CanSIPsv2, and COLA-RSMAS-CCSM4 models.

The sea surface temperature (SST) forecast is for the present weak La Niña conditions to transition into ENSO neutral conditions and to remain neutral through the boreal summer, with a possible regeneration of La Nina starting next boreal winter. SST forecasts in the tropical Indian and Atlantic Oceans are for normal or slightly warmer than normal conditions in the coming seasons.

Precipitation forecasts are for enhanced probabilities of above-normal precipitation in large parts of India in May-Jul and Jun-Aug, in parts of Indonesia in Jun-Aug, Jul-Sep, and Aug-Oct, in South Eastern Australia for Jul-Sep and Aug-Oct, and in the Sahel for all forecasted seasons. Forecasts are for enhanced probabilities of below-normal precipitation in the Northwest United States and Southwest Asia in May-Jul and Jun-Aug, in Southern Mexico and Central America in Jun-Aug and Jul-Sep, in the Atlantic coast of Northern South America and Southern West Africa in Jun-Aug, Jul-Sep, and Aug-Oct, and in Chile for all forecasted seasons.

In May-Jul, Jun-Aug, and Jul-Sep enhanced probabilities of above normal temperatures are forecast for the Western United States, Eastern Canada, Greenland, the Mediterranean Basin, and Northern Russia, while enhanced probabilities of below-normal temperatures are forecast for parts of India.

Citation

Kirtman, B., D. Min, J. Infanti, J. Kinter, D. Paolino, Q. Zhang, H. van den Dool, S. Saha, M. Mendez, E. Becker, P. Peng, P. Tripp, J. Huang, D. DeWitt, M. Tippett, A. Barnston, S. Li, A. Rosati, S. Schubert, M. Rienecker, M. Suarez, Z. Li, J. Marshak, Y. Lim, J. Tribbia, K. Pegion, W. Merryfield, B. Denis, and E. Wood, 2014: The North American Multimodel Ensemble: Phase-1 Seasonal-to-Interannual Prediction; Phase-2 toward Developing Intraseasonal Prediction. Bull. Amer. Meteor. Soc., 95, 585–601, doi: 10.1175/BAMS-D-12-00050.1.