Summer 2025 Weather Forecast for the U.S. and Canada

As of March 24, 2025, NOAA indicates that the La Niña phase, likely peaking in winter 2024–2025, will be fading by summer, transitioning toward neutral ENSO conditions. This weakening La Niña will reduce the intensity of cold air outbreaks in North America, but its lingering effects could still amplify storminess in the Pacific Northwest and parts of Canada early in the season. The polar vortex, typically weakening by late spring, will play a minimal role by summer, allowing warmer subtropical air to dominate. Data from severe-weather.eu suggests a high-pressure anomaly over the central U.S. and a disturbed pressure pattern over Canada, hinting at a hotter-than-average summer for much of the U.S. and a mixed bag for Canada.

Summer 2025 United States: Regional Trends

Northeast (New York, Boston, Philadelphia)
Summer 2025 in the Northeast looks to be warm and humid, with average highs ranging from 80°F to 90°F (27–32°C) in June and peaking at 85°F to 95°F (29–35°C) in July and August. Nighttime lows will hover around 65°F to 75°F (18–24°C). Expect above-average rainfall, around 4–6 inches per month, driven by Atlantic moisture and occasional stalled fronts. Early June might see cooler spells (highs in the 70s°F / 21–26°C) due to residual La Niña influences, but July and August could bring heatwaves with temperatures pushing into the upper 90s°F (35–37°C), especially in urban areas like Philly. Humidity will make it feel stickier than usual, with a higher-than-normal chance of thunderstorms.

Southeast (Atlanta, Miami, Houston)

The Southeast is gearing up for a hot and steamy Summer 2025. Daytime highs will average 90°F to 100°F (32–38°C), with Miami staying in the low 90s°F (32–34°C) but feeling like 105°F+ (40°C+) due to oppressive humidity. Nighttime lows won't dip much below 75°F to 80°F (24–27°C). Rainfall will vary: the Gulf Coast (e.g., Houston) could see 6–8 inches monthly from tropical systems, while inland areas like Atlanta might get 4–5 inches, slightly above normal. Severe-weather.eu points to a high-pressure ridge amplifying heat in July, potentially pushing temps to 100°F+ (38°C+) for extended periods. Watch for an active hurricane season spilling into August, especially along the Gulf and Atlantic coasts.

Midwest (Chicago, St. Louis, Minneapolis)

The Midwest will likely bake under a persistent high-pressure dome, as hinted by severe-weather.eu's anomaly maps. Average highs will range from 85°F to 95°F (29–35°C), with July and August potentially hitting 100°F (38°C) during heatwaves. Nighttime lows will sit at 65°F to 75°F (18–24°C). Rainfall could be below average (2–4 inches per month) due to this ridge, raising drought concerns by late Summer 2025, especially in the Upper Midwest. Early June might bring some stormy weather from clashing air masses, but dry, scorching conditions will dominate later. Chicago's urban heat island could push perceived temps even higher.

Southwest (Phoenix, Las Vegas, Albuquerque)

The Southwest is in for a blistering summer, with average highs soaring from 100°F to 110°F (38–43°C) in June to 105°F to 115°F (41–46°C) in July and August. Phoenix might flirt with 120°F (49°C) during peak heatwaves. Nighttime lows will struggle to drop below 80°F to 90°F (27–32°C). Monsoon activity, typically kicking in by July, could bring 1–3 inches of rain, slightly below average, per ECMWF trends. The high-pressure anomaly over the central U.S. will amplify arid conditions, making this a Summer 2025 of relentless heat and limited relief.

West Coast (Los Angeles, Seattle, San Francisco)

The West Coast will see a split story. Southern California (e.g., LA) will be hot and dry, with highs of 85°F to 95°F (29–35°C) inland and 75°F to 85°F (24–29°C) along the coast; lows around 60°F to 70°F (16–21°C). Rainfall will be negligible (<0.5 inches). Northern areas like Seattle will be milder, with highs of 70°F to 80°F (21–27°C) and lows of 50°F to 60°F (10–16°C), but wetter than normal (2–3 inches monthly) due to a disturbed pressure pattern over the Pacific Northwest. Severe-weather.eu suggests cooler, cloudier conditions in the north contrasting with baked, sunny skies in the south.

Canada: Regional Trends

Western Canada (Vancouver, Calgary, Edmonton)
Western Canada will experience a varied Summer 2025. Vancouver will see highs of 68°F to 78°F (20–26°C) and lows of 50°F to 60°F (10–16°C), with above-average rain (3–4 inches monthly) tied to Pacific storms. Inland, Calgary and Edmonton will hit 75°F to 85°F (24–29°C) during the day, dropping to 45°F to 55°F (7–13°C) at night. Rainfall here might be near normal (2–3 inches), but severe-weather.eu's pressure disturbance hints at wild swings—think cool, wet spells in June and scorching heat (up to 90°F / 32°C) in July. Wildfire risk could spike in dry pockets by August.

Central Canada (Winnipeg, Toronto, Ottawa)

Central Canada looks warm and stormy. Highs will range from 75°F to 85°F (24–29°C) in June, climbing to 80°F to 90°F (27–32°C) in July and August; lows will be 55°F to 65°F (13–18°C). Rainfall could hit 4–6 inches monthly, above average, with Toronto and Ottawa seeing frequent thunderstorms. Winnipeg might dodge some of the wettest weather (3–4 inches), but heatwaves could push temps to 95°F (35°C) in July. The fading La Niña may fuel early-season instability, easing into a muggy, warm pattern later.

Eastern Canada (Quebec City, Halifax)

Eastern Canada will lean warm and wet. Highs will average 70°F to 80°F (21–27°C) in June, rising to 75°F to 85°F (24–29°C) in July and August; lows around 50°F to 65°F (10–18°C). Rainfall will be plentiful (4–6 inches monthly), with Halifax potentially seeing 6–8 inches from Atlantic systems. Severe-weather.eu notes a disturbed pressure pattern, suggesting cooler, cloudier stretches in June before heat builds in August. Coastal fog could linger, but inland areas like Quebec City might hit 90°F (32°C) during brief hot spells.

General Trends and Anomalies

Temperature: Summer 2025 will likely be 1–3°F (0.5–1.5°C) warmer than the 1991–2020 average across most of the U.S. and southern Canada, with the central U.S. and Southwest seeing the biggest heat anomalies.
Precipitation: Wetter-than-normal conditions are expected in the Northeast U.S., Southeast coasts, and much of Canada; drier-than-normal in the Midwest and Southwest U.S.
La Niña Fade: Early summer might feel its residual storminess, but neutral ENSO by August will favor heat over cold snaps.
Pressure Patterns: A high-pressure ridge over the U.S. will drive heat, while a disturbed pattern over Canada keeps weather more volatile.

Wrap-Up

Summer 2025 promises a scorcher for much of the U.S., with the Southeast and Southwest sweating the most, while the Northeast and Midwest juggle heat and storms. Canada will see a milder, wetter season, especially in the west and east, with central areas catching some of that U.S. heat. Keep an eye on updates as we get closer—long-range forecasts are a roadmap, not a crystal ball!

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