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Philadelphia weekend weather

This weekend in Philadelphia, PA, model by model. Weekend forecasts are far enough out that the models often split - so we show you where.

Weekend

The models centre on about 76° across the weekend. Agreement is low - the weekend is genuinely up in the air at this range. Rain chance reaches 82% on at least one model.

Tomorrow

2026-09-19 — every model, side by side
NWSNational Blend (NBM)
75°
Partly cloudy
High 75°·Low 62°·Rain 3%
AmericanNOAA GFS
74°
Cloudy
High 74°·Low 63°·Rain 3%
EuropeanECMWF
76°
Cloudy
High 76°·Low 64°·Rain 2%

All 3 models land within 2° of each other for this day — that is a forecast you can plan on.

Sun

2026-09-20 — every model, side by side
NWSNational Blend (NBM)
76°
Drizzle
High 76°·Low 64°·Rain 70%
AmericanNOAA GFS
73°
Heavy rain
High 73°·Low 63°·Rain 70%
EuropeanECMWF
82°
Light rain
High 82°·Low 64°·Rain 82%

The models are 9° apart on this day. That is genuine uncertainty — any app showing you a single confident number is hiding it.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±3°82° to 85°±40%16% to 56% chance
Tomorrow±2°74° to 76°±1%2% to 3% chance
Sun±9°73° to 82°±12%70% to 82% chance
Mon±2°69° to 71°±1%70% to 71% chance
Tue±4°61° to 65°±10%25% to 35% chance

The models often agree on temperature and still split on rain, and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.

Common questions

Will it rain this weekend?
At least one model puts the weekend rain chance as high as 82%. Weekend forecasts sit far enough ahead that models frequently disagree on showers - when they do, no single app can honestly tell you it will or will not rain.
How reliable is a weekend forecast?
It depends how far away the weekend is. Forecast error grows steadily with lead time, so a Saturday forecast made on Friday is far stronger than one made the previous Monday. The honest signal is model agreement: when they converge the forecast is solid, and when they spread the weekend is genuinely uncertain.

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