CFS V2 Projects Hot July Southwest Plains to New England and Eventually California

Climate Impact Company Week 2-4 Outlook

North America

Issued: Tuesday, June 24, 2025

Highlight: New England heatwaves; Southwest intense heat spreads from Western Texas to California.

Charts of the day: CFS V2 July 2025 Outlook

Discussion: The CFS V2 month ahead forecast for the U.S. valid July 2025 indicates widespread above normal temperature from the southern Great Plains and Texas to the Northeast U.S. The southern Great Plains and Texas are where the hottest daytime temperature anomalies occur due to the combination of heat and drier than normal mid-summer climate. While abundant thundershower activity across the Midwest to the Mid-Atlantic suggests the primary contributor to above normal temperature is high humidity and elevated nighttime temperature. The New England heat could be impressive. CFS V2 projects the center of an upper-level high pressure ridge across New England.

Week-2 Ahead Forecast valid June 29-July 5, 2025: Hot Central to Northeast; Wet Mid-south.

Discussion: For consistency, the CFS V2 is utilized to project the week 2-4-outlook. In early July, CFS V2 indicates an East Coast high-pressure ridge responsible for hot and humid weather across the Central and East U.S. with exception of the Mid-south region where rainfall suppresses heat risk. The forecast trend is hotter Central and wetter northwest Gulf States.

Week-3 Ahead Forecast valid July 6-12, 2025: Intense Southwest U.S. heat.

Discussion: CFS V2 projects an upper ridge over California and New England. The primary change to the outlook is hotter across the Southwest U.S. including Western Texas and the southwest Great Plains. This zone is threatened by extreme heat. The East is not quite as hot as previously indicated. Midwest and Southeast U.S. thunderstorms are dominant while elsewhere is mostly dry.

Week-4 Ahead Forecast valid July 13-19, 2025: California and New England heatwave.

Discussion: CFS V2 indicates two high pressure ridge areas: Northeast U.S. and California. The West Coast ridge is the strongest. The ECM “weeklies” are similar therefore forecast confidence is reasonable. Expect a California and New England heatwave as the hottest part of summer approaches.