Extreme Heat Seasonality Shifts Pose New Business Risks

Two recent analyses point to a common bottom line for businesses: the calendar no longer reliably predicts when extreme heat will strike. A NASA-backed reanalysis of 45 years of weather data, highlighted by AGU Eos, finds that the seasonality of both dry and humid heat extremes has shifted substantially. Meanwhile, WIRED reports that current record-breaking heat in parts of the U.S. is being amplified by El Niño on top of the steady warming from fossil fuels.

The sources agree that extreme heat is becoming more frequent and intense, but they differ in emphasis. The Eos study focuses on the changing timing of heat events—meaning heat waves can arrive earlier or later than historical norms. WIRED's piece centers on the immediate intensity boost from El Niño, which is shattering records this season. Together, they suggest that businesses relying on seasonal planning—from energy demand forecasting to outdoor labor schedules and supply chain logistics—can no longer assume a stable heat season.

For the business section, the takeaway is that climate risk is not just about hotter summers, but about unpredictability. Companies that invest in adaptive infrastructure, flexible workforce policies, and dynamic risk models will be better positioned than those that stick to static seasonal assumptions. The sources do not provide specific cost estimates, but the implication is clear: the financial impact of heat is spreading across more months of the year.We need to produce strict JSON with the given keys. The sources are about climate/weather, but we need to write for Business section. We'll frame it as business implications. Headline under 80 chars. Dek one sentence. KeyPoints exactly 3. Body 2-4 short paragraphs markdown. Ensure we don't invent facts. Use only what's in sources. Note agreement and difference. Let's craft.```json {