How far extreme-weather readings and effects can reach
Temperatures at Selagoncy and Olenek, Met Office's rainless July, a strengthening El Niño and smoke from Canadian fires show extreme conditions spanning local to intercontinental scales.
Science··Evening
Heat at one point, dryness across a network
The thermometer at Selagoncy meteorological station, near the edge of the Arctic Circle, read 33.9 degrees Celsius, while Olenek reached 32.7 degrees. Climatologist Maximiliano Herrera compiled the Ogimet data reported by Scientific American. Those temperatures describe measurements made at particular stations at particular moments; the rate of regional warming comes from longer series. During the same summer, a British station network showed another form of extreme conditions sustained across a month. Provisional Met Office figures seen by New Scientist showed no rain through July at at least 20 stations, while England and Wales experienced their driest July in 190 years. Southern England averaged 1.5 millimetres of rain, 2 per cent of its 1991–2020 average, and mean temperatures were 3.2 degrees Celsius above normal. Kew Gardens had its first rainless July since measurements began there in 1871. Heathrow's dry spell reached 42 days, a duration unseen since measurements began there in 1948. One development is a high value on individual thermometers; the other is a month of empty rain gauges across many sites. Both make extreme conditions concrete, though one is a point reading and the other is persistence spread across a wider region.[1], [2]
From the Pacific to the global season
WMO, the World Meteorological Organization, says in its seasonal assessment that a strengthening El Niño is expected to shape global weather patterns from August through October. Seasonal mean sea-surface temperature anomalies in the key monitoring regions are forecast to exceed 2.9 degrees. The assessment draws on multi-model ensembles from leading global producing centres, and a fuller El Niño/La Niña update is due in early September. El Niño is defined by above-average sea-surface temperatures in the central and eastern equatorial Pacific and is one of the main drivers of climate variability from year to year. Events recur every two to seven years, usually last nine to twelve months and commonly peak between November and February. Their strongest influence on global mean temperature often arrives in the year after onset. The same ocean signal, however, does not yield an identical outcome everywhere. Regional effects vary with the event's intensity, duration and timing, as well as its interaction with other modes such as the Indian Ocean Dipole. WMO's call for preparation therefore concerns more than one local weather event: an equatorial ocean temperature pattern carries changing probabilities into many regions over a period of months.[3]
Smoke travelling from fire zones into energy systems
Smoke rising from Canada's 2023 wildfire season supplied a direct example of an effect travelling far from its source. The study reported by New Scientist calculated that drifting smoke lowered solar-electricity generation across both North America and Europe over five months. The consequences of the fires therefore extended beyond the burning forests and nearby air quality into electricity production on another continent. Cooling from the smoke made solar panels somewhat more efficient, so the calculation included that partly offsetting effect; the overall result still showed lower generation as smoke reduced the available light. Taken together, the day's four developments widen the geographic scale step by step. Heat at Selagoncy and Olenek appears in individual station readings; Met Office figures show British drought persisting across a station network for a month; WMO's El Niño assessment alters seasonal probabilities around the world; and Canadian smoke reaches solar generation on two continents. The place where a measurement is made and the place where a consequence is felt need not coincide. An extreme condition can remain a local indicator, or it can become part of a regional or intercontinental chain carried through the atmosphere and ocean.[1], [2], [3], [4]
