A dangerous, multi-day heat wave begins Sunday across the Delmarva Peninsula, with highs climbing into the upper 90s and heat index values reaching up to 110°F. The heat is expected to peak Monday and Tuesday, with potential to tie or break longstanding temperature records. Overnight relief will be minimal, and prolonged exposure could lead to serious health risks. While some moderation is expected later in the week, extreme heat remains a top concern through at least midweek.

Sussex County will enjoy a brief reprieve from the heat Friday night into Saturday, but steamy conditions and dangerous heat index values are expected to return by Sunday and continue into early next week.