Abstract
Heatwaves have intensified across many regions due to ongoing warming, leading to significant environmental and societal impacts. The present study characterizes heatwave regimes across two contrasting subtropical regions of Mexico: the arid‐to‐semiarid northwest and the humid tropical Yucatán Peninsula. Using a station‐based percentile framework that enables consistent inter‐regional comparison, we identify marked differences in heatwave occurrence, intensity, and seasonal timing. In northwestern Mexico, heatwaves were characterized by higher peak temperatures occurring at a mean annual rate of approximately 0.16 events per year, with events clustering between June and August. In contrast, the Yucatán Peninsula exhibited a relatively higher occurrence rate (~0.33 events per year), with events concentrated between April and June before the onset of the rainy season. Station‐averaged event duration was concentrated in the 3–4‐day interval in NW and in the 4–5‐day interval in YP. These contrasts are further quantified through station‐based probabilities of heatwave occurrence derived from annual event counts, supporting the identification of two distinct heatwave regimes and providing a quantitative baseline for comparative climatological analyses and monitoring.