WEC · 10-Q · 2026Q2 · Full report

Weather Impact on Demand

WEC ENERGY GROUP, INC. · 2026-08-04 · Importance 35 · Surprise 48

Unfavorable spring weather reduced Wisconsin second-quarter 2026 margins by $20.4 million compared with the second quarter of 2025. The combined WE and WG service area experienced heating degree days 20.4% below the prior-year quarter, while cooling degree days were 23.9% lower in the combined WE and WG area and 28.1% lower in the WPS area. The weather-related margin reduction was substantially offset by a $20.2 million increase from weather-normalized customer growth, driven by very large customers. Illinois heating degree days were 19.2% below normal, and MGU heating degree days were 17.0% below normal, contributing to lower residential gas sales and margins.

Key facts

• The margin impact from unfavorable spring weather was $20.4 million during the second quarter of 2026 compared with the same quarter in 2025. source
• As measured by heating degree days, the second quarter of 2026 was 20.4% warmer than the same quarter in 2025 in the combined WE and WG service area. source
• As measured by cooling degree days, the second quarter of 2026 was 23.9% colder than the same quarter in 2025 in the combined WE and WG service area. source
• As measured by cooling degree days, the second quarter of 2026 was 28.1% colder than the same quarter in 2025 in the WPS service area. source
• The margin impact from unfavorable weather was $28.9 million during the six months ended June 30, 2026, compared with the same period in 2025. source
• Heating degree days for WE and WG were 3,959 for the six months ended June 30, 2026, which was 7.8% warmer than the same period in 2025. source