Summer in the Imperial Valley means air conditioning running from morning to night, and that is the heaviest, longest load most electrical systems ever carry. Panels, breakers, and connections that are fine in winter can start failing in August.
Heat makes it worse. A panel mounted on a sun-facing outside wall runs hot before any load is added, and every connection inside expands and contracts daily. Over time that loosens terminals, and loose terminals create more heat.
Warning signs include breakers that trip on the hottest afternoons, lights that dim when the AC kicks on, warm outlets, and buzzing at the panel. Any of these is worth a call before the next heat wave, not during it.
Spring is the best time for panel maintenance: tightening connections, cleaning out dust, and checking that the AC circuit and breaker are sized correctly. Adding a new unit or a second system? Have the panel's capacity checked first.