Exhibit 99.1 FOR IMMEDIATE RELEASE AVANGRID REPORTS SECOND QUARTER 2024 FINANCIAL RESULTS Contacts: Analysts: Charlotte Ancel, Charlotte.Ancel@Avangrid.com, 203-997-7366 Media: Leo Rosales, Leo.Rosales@Avangrid.com, 518-419-2401 • Delivered first half 2024 earnings of $1.34 per share and adjusted earnings of$1.37 per share, +58% & +61% year-over-year, respectively • Executed on multi-year rate plans in New York and Maine, including more than $9 billion of investment authorized for cost recovery in New York ...