United States
Sensitive Rain Seasons
- Winter–Spring (December–March): Primary period of strong teleconnection: wet and cool in south, warm and mild in north.
- Hurricane season (June–November): Strong vertical wind shear in the tropical Atlantic typically suppresses Atlantic basin hurricane frequency.
Primary Environmental Hazards
- • Heavy winter rainstorms and atmospheric river events in California, triggering mudslides and flooding
- • Wet and stormy conditions along the Gulf Coast and Florida, with elevated tornado risks
- • Significantly warmer-than-normal winters across the Pacific Northwest, Northern Plains, and Upper Midwest
- • Suppression of Atlantic hurricane development due to strong westerly upper-level wind shear
- • Increased winter snowpack across the southern Sierra Nevada and southern Rockies
Current 2026–27 El Niño Context for United States
With CPC placing greater than 90% odds on a very strong El Niño through winter 2026–27, the southern tier of the US faces high probabilities of an active storm track, heavy rains in California and the Gulf Coast, and a mild northern winter.
Major Monitored River Basins in United States
Mississippi River Lower Basin
29.95° N, 90.07° WDrains over 40% of the contiguous US into the Gulf of Mexico.
Sacramento-San Joaquin Delta
38.00° N, 121.75° WHeart of California's water conveyance system; vulnerable to atmospheric river surges.
Colorado River Basin
36.00° N, 114.74° WCritical water supply for the American Southwest; monitored at Lake Mead.
Monitored Cities in United States
Select any city below for real-time temperature, 7-day rainfall forecasts, and live flood risk score:
Los Angeles
34.1° N, 118.2° WHouston
29.8° N, 95.4° WNew York
40.7° N, 74.0° WChicago
41.9° N, 87.6° WMiami
25.8° N, 80.2° WSan Francisco
37.8° N, 122.4° WSeattle
47.6° N, 122.3° WHistorical El Niño Events in United States
1982–83 Event
Relentless storms hammered coastal California, causing historic cliff erosion and highway collapses.
1997–98 Event
Classic "Super El Niño" brought record winter storminess, flooding, and tornadoes across Florida and California.
2015–16 Event
Very strong event delivered milder northern temperatures and southern moisture.
2023–24 Event
Stormy southern jet brought record atmospheric rivers and drought relief to California.