When will El Niño peak?

(NEXSTAR) – National forecasters made it official this month: El Niño is here. But we might not feel the effects of it just yet.

“Historically El Niño events during the summer tend to have very weak impacts over the United States,” explained National Weather Service meteorologist Michelle L’Heureux. “Another way of phrasing that is that El Niño’s impacts can often be unreliable in the summer, and not repeat from one El Niño event to the next El Niño event.” 

But as the year goes on, El Niño is expected to build strength until it peaks in winter, between December and February. That’s when we’re most likely to feel “typical” El Niño effects.

In the U.S., that means the entire southern third to half of the United States, including California, is likely to be wetter in El Niño. (Exactly where that dividing line falls varies from year to year.) Meanwhile, the U.S. Pacific Northwest and parts of the Ohio Valley tend to be dry and warm.

Hawaii also often sees below-average rain during an El Niño year.

As we wait for peak El Niño to set in, the southern hemisphere will be feeling some of its impacts.

El Niño strongly tilts Australia toward drier and warmer conditions with northern South America — Brazil, Colombia and Venezuela — likely to be drier and Southeast Argentina and parts of Chile likely to be wetter, she said. India and Indonesia also tend to be dry through August in El Niños.

The Associated Press contributed to this report.