Earthlog · Weather and supply
Where rain is running far from normal in the regions that grow the world's food, feed its rivers and canals, and host its mines, and what the Pacific's El Niño or La Niña cycle usually means for them. Weather is an early signal for harvests, food prices, export taxes and government revenue.
| Region | Status | 90 days vs normal |
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How to read this. For each region we add up the rain over the last 30 and 90 days and rank it against the same dates in each of the last 25 completed years (2001 to last year). A 1991–2020 comparison was tried first, but recent years proved much more variable than that older period, so it flagged too many regions as extreme. A rank of 8 or lower means one of the driest years on record in that span; 92 or higher means one of the wettest. The 90-day window sets the status; the 30-day figures are shown beside it. Very dry and Very wet are those extremes; Dry and Wet are the next band in. Where normal rainfall is very low at this time of year (a desert or the dry season) the comparison is skipped, because a few millimetres either way means little.
El Niño and La Niña. The Oceanic Niño Index (ONI) is NOAA's official measure: the temperature of the central tropical Pacific against its long-run normal, as a three-month average. At +0.5 or above it counts as El Niño, at −0.5 or below La Niña, and the bigger the number the stronger the event. The Indian Ocean Dipole is a similar swing in the Indian Ocean. The "usually" column is the typical tendency from climate research, shown only for months when it applies. It is a tilt in the odds, not a forecast, and some links are weak.
What it is not. Rain at one point is not a crop forecast, a river level or a reservoir level. Soil, temperature, irrigation, snowmelt and timing all matter. Satellite-based rainfall estimates are coarser than a rain gauge and trail real time by about three days. The official NOAA ENSO status (Watch, Advisory and so on) is published only as text, so it is not shown here; the latest is on the NOAA Climate Prediction Center page.
Sources: NASA POWER (rainfall), NOAA Climate Prediction Center (ONI, Niño 3.4), NOAA Physical Sciences Laboratory (MEI.v2, Indian Ocean Dipole).