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Nerd mode: every forecast, readouts, filters and range & bearing for weather enthusiasts

This week’s weatherSão Paulo, Brazil

Rain is likely in São Paulo on Thursday

9 in 10 of NOAA’s 31 GEFS forecasts bring measurable rain to São Paulo Thu 3–9 p.m. GMT-3; 5 in 10 bring 2.5 mm or more.

NOAA GEFS, 31 forecasts · Mon 28 Sep 18Z run · updated Mon., Sept. 28, 8:03 p.m. GMT-3 · times are São Paulo’s (GMT-3)

See it on the globe For warnings, follow your national weather service.

Quick answers

Will it rain in São Paulo this week?
The best chances of measurable rain: Tuesday (5 in 10 forecasts, 9 p.m.–3 a.m.); Wednesday (5 in 10 forecasts, 9 p.m.–3 a.m.); Thursday (9 in 10 forecasts, 3–9 p.m.); Friday (8 in 10 forecasts, 9 p.m.–3 a.m.). Times are GMT-3.
How much rain will São Paulo get this week?
By Mon., Oct. 5, 3 p.m. GMT-3 (the end of the forecast), the middle forecast has 43 mm of rain and melted snow, counting from Mon 9 p.m. 9 in 10 forecasts bring 25 mm or more in total; 4 in 10 forecasts bring 51 mm or more.
How windy will it get in São Paulo?
Gusts over 48 km/h: 2 in 10 forecasts at Sun 9 a.m. GMT-3. The middle forecast’s strongest gust is 36 km/h, Sun 9 a.m. Checked every six hours, so a brief peak can fall between.
How warm or cold will it be in São Paulo?
At the six-hourly times, the middle forecast runs from 16°C (Sat 3 a.m.) to 32°C (Wed 3 p.m.) GMT-3. The day’s real high and low can fall between those times.
Are any storms heading for São Paulo?
No storm Stormlines tracks has 1 in 10 forecasts passing its centre within 160 kilometres of São Paulo this week.

Chance of rain, six hours at a time

Mon 9 p.m.–3 a.m.: 5 in 10 forecasts with measurable rain; middle forecast almost noneTue 3–9 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 9 a.m.–3 p.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneTue 3–9 p.m.: 2 in 10 forecasts with measurable rain; middle forecast almost noneTue 9 p.m.–3 a.m.: 5 in 10 forecasts with measurable rain; middle forecast 0.4 mmWed 3–9 a.m.: fewer than 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 9 a.m.–3 p.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneWed 3–9 p.m.: 5 in 10 forecasts with measurable rain; middle forecast almost noneWed 9 p.m.–3 a.m.: 8 in 10 forecasts with measurable rain; middle forecast 0.7 mmThu 3–9 a.m.: 8 in 10 forecasts with measurable rain; middle forecast 0.7 mmThu 9 a.m.–3 p.m.: 9 in 10 forecasts with measurable rain; middle forecast 1.0 mmThu 3–9 p.m.: 9 in 10 forecasts with measurable rain; middle forecast 2.4 mmThu 9 p.m.–3 a.m.: 8 in 10 forecasts with measurable rain; middle forecast 0.8 mmFri 3–9 a.m.: 8 in 10 forecasts with measurable rain; middle forecast 1.5 mmFri 9 a.m.–3 p.m.: 7 in 10 forecasts with measurable rain; middle forecast 0.6 mmFri 3–9 p.m.: 5 in 10 forecasts with measurable rain; middle forecast almost noneFri 9 p.m.–3 a.m.: 3 in 10 forecasts with measurable rain; middle forecast almost noneSat 3–9 a.m.: 4 in 10 forecasts with measurable rain; middle forecast almost noneSat 9 a.m.–3 p.m.: 9 in 10 forecasts with measurable rain; middle forecast 2.1 mmSat 3–9 p.m.: 9 in 10 forecasts with measurable rain; middle forecast 1.6 mmSat 9 p.m.–3 a.m.: 3 in 10 forecasts with measurable rain; middle forecast almost noneSun 3–9 a.m.: 1 in 10 forecasts with measurable rain; middle forecast almost noneSun 9 a.m.–3 p.m.: 6 in 10 forecasts with measurable rain; middle forecast 0.4 mmSun 3–9 p.m.: 9 in 10 forecasts with measurable rain; middle forecast 2.9 mmSun 9 p.m.–3 a.m.: 9 in 10 forecasts with measurable rain; middle forecast 3.4 mmMon 3–9 a.m.: 8 in 10 forecasts with measurable rain; middle forecast 4.0 mmMon 9 a.m.–3 p.m.: 8 in 10 forecasts with measurable rain; middle forecast 3.5 mm

Each bar is the share of the 31 forecasts with measurable rain or melted snow in that six hours; the darker the bar, the more forecasts agree. Local days, GMT-3.

The week, day by day

DayChance of rain2.5 mm or moreTotal by day’s endStrongest gustTemperature
Mon 28 (rest of day)–––18 km/h20°C
Tue 295 in 10<1 in 100.4 mm · <1 in 1023 km/h19°C–32°C
Wed 305 in 101 in 101.4 mm · <1 in 1025 km/h21°C–32°C
Thu 19 in 105 in 107.5 mm · 2 in 1018 km/h19°C–23°C
Fri 28 in 104 in 1014 mm · 5 in 1021 km/h16°C–18°C
Sat 39 in 104 in 1018 mm · 8 in 1022 km/h16°C–22°C
Sun 49 in 106 in 1027 mm · 9 in 1036 km/h18°C–28°C
Mon 5 (part)9 in 106 in 1043 mm · nearly all25 km/h20°C–25°C

Chances are the highest in any six hours of the day. “Total by day’s end” is the middle forecast’s running total since Mon 9 p.m., and the share of forecasts with 13 mm or more by then; totals aren’t added up day by day, because the middle forecast of each day isn’t the same forecast. Gusts and temperatures are read every six hours.

Storms near São Paulo

No storm Stormlines tracks has 1 in 10 forecasts passing its centre near São Paulo this week. Every storm we’re tracking →

About these numbers

They come from one source, NOAA’s Global Ensemble Forecast System (GEFS): 31 runs of the same model, each started slightly differently, read at São Paulo’s coordinates on a grid about 55 km (35 miles) apart. “8 in 10 forecasts” means 8 in 10 of those runs. Nothing is adjusted for local effects such as coasts, lakes, hills or city heat, so the numbers can differ from your local official forecast, especially for snow and showers.

“Measurable rain” counts rain or melted snow in a six-hour period. Not an official forecast: follow your national weather service for warnings and decisions. How the forecasts are read: how to read the maps and the glossary.

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