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Osasco weather by month: averages, rainfall & climate trends

Temperature-wise, the seasons in Osasco are gentle: monthly means drift only 6.2°C over the whole year. Rainfall leans toward the stretch from October to March. Osasco weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+0.3°Chigh near average

24° / 14°Today
24° / 16°Average
see today in detail →

How it's changed

+1.4°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4962days above 30°C a year now (2016–2025) · 6 in the 1940sdays above 30°C · 6 in the 1940s+1.4°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 211 mmhigh 27°low 19°February, rain 181 mmhigh 27°low 19°March, rain 160 mmhigh 27°low 19°April, rain 76 mmhigh 25°low 17°May, rain 67 mmhigh 23°low 14°June, rain 50 mmhigh 22°low 13°July, rain 49 mmhigh 22°low 12°August, rain 43 mmhigh 24°low 13°September, rain 86 mmhigh 25°low 15°October, rain 132 mmhigh 25°low 16°November, rain 147 mmhigh 25°low 17°December, rain 200 mmhigh 26°low 18°wettest month January, 211 mm · 1,404 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

15.5°

16°feels like
90%humidity
14°dew point
6 km/hfrom SE
UV index0.0
sunrise05:31sunset18:13day length12h 42m
SunPartly cloudy24°14°
TodayPartly cloudy23°15°
TuePartly cloudy23°14°
WedOvercast23°15°
ThuOvercast23°16°
FriLight rain22°17°
SatOvercast24°18°

On this date: October 19

Today (forecast)
24° / 14°
Average for October 19
24° / 16°

High near average · +0.3°C

  • Highest since 1940: 36.5° · 2014
  • Lowest since 1940: 11.8° · 1971
  • One year ago: 18° / 12°

Every October 19 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 19 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Osasco is sampled from the ECMWF ERA5 reanalysis at 23.53°S, 46.79°W, with daily records since 1940.

Coordinates
23.53°S, 46.79°W
Time zone
America/Sao Paulo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

20 of the last 31 days were warmer than the historical average for that date. Average difference: +0.8°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

The year peaks in February, at around 27.4°C by mid-afternoon, with nights around 19.3°C. Around 65 nights a year stay above 20°C. At the other extreme, July brings afternoon highs of about 21.9°C and typical overnight lows of 12.4°C.

In total, Osasco averages about 1,404 mm of precipitation a year; January is usually the wettest month (211 mm) and August the driest (43 mm). A typical year brings rain or snow on around 137 days.

Comparing the record's first decade with its most recent one, Osasco now averages 1.4°C warmer than it did in the 1940s. The count of days past 30°C has risen from roughly 6 a year to 60 between the record's first and last decades.

Climate graph (climograph)

February is the warmest month, July the coolest: a yearly swing of 6°C. Wettest month: January (~211 mm). Whole year averages ~1,404 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 137 rainy days a year: most in January (~20), fewest in August (~4).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Osasco month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January27.1°19.2°211 mm2013.3 h34.7° (2015)11.9° (1980)
February27.4°19.3°181 mm1812.8 h36.0° (2014)13.2° (1991)
March26.6°18.6°160 mm1612.2 h33.1° (2025)12.0° (1961)
April25.0°16.8°76 mm911.4 h32.0° (1996)6.7° (1971)
May22.8°14.5°67 mm610.9 h31.6° (2024)4.5° (1979)
June21.9°13.1°50 mm510.6 h28.9° (2010)1.8° (1981)
July21.9°12.4°49 mm510.7 h29.6° (1983)2.5° (2021)
August23.6°13.3°43 mm411.2 h33.5° (2005)3.7° (1984)
September24.7°14.9°86 mm811.9 h37.0° (1961)5.5° (2002)
October25.0°16.3°132 mm1312.6 h37.2° (2020)7.9° (1974)
November25.5°17.0°147 mm1413.2 h36.5° (2023)9.4° (1949)
December26.3°18.3°200 mm1913.4 h34.3° (2025)11.5° (1951)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.4°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.21°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.27°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 5.5 early in the record → 61.7 recently. Frost days: 0 → 0.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2020, coldest in 1981: 37.2°C / 1.8°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,404 mm/year on average. Last decade: −14% vs that average. Long-term trend: −30 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Osasco

Which is the warmest month in Osasco?
On long-term average, the warmest month in Osasco is February (mean daily temperature of about 22.7°C) and the coolest is July (about 16.5°C).
How does today's temperature in Osasco compare to the historical average?
On October 19, 2026, Osasco is forecast to reach a high of 24.3°C and a low of 13.8°C. The long-term average for this date (the full record since 1940) is a high of 24.0°C and a low of 16.1°C, so today's high is about equal to that average.
How much has Osasco warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Osasco is about 1.4°C warmer.
How much does it rain in Osasco?
Osasco receives about 1,404 mm of precipitation per year on long-term average, with January typically the wettest month.
What is the average temperature in Osasco?
Over the full record (since 1940), the annual mean temperature in Osasco is about 19.8°C. The warmest month is February and the coolest is July.
What are the average temperatures in Osasco by month?
Average daily highs and lows for each month in Osasco (°C, full record since 1940): January 27°/19°, February 27°/19°, March 27°/19°, April 25°/17°, May 23°/14°, June 22°/13°, July 22°/12°, August 24°/13°, September 25°/15°, October 25°/16°, November 25°/17°, December 26°/18°.
What is the weather like in Osasco in summer?
December to February is summer in Osasco, and it is wet and warm. Expect 26–27°C by day and 18–19°C at night, with February the warmest month. Rain falls on about 19 days a month, adding up to around 198 mm. No season is wetter.
What is the weather like in Osasco in winter?
June to August is winter in Osasco, and it is pleasantly warm. Daytime highs sit at 22–24°C and nights at 12–13°C; July is the coldest month. Rain is steady at around 48 mm a month, spread over roughly 5 days. No season is drier.
What is the weather like in Osasco in spring?
Spring in Osasco (September to November) is wet and pleasantly warm. Afternoons run 25°C and nights 15–17°C; November is the warmest month. Rain picks up through the season: 8 rainy days and 86 mm in September, 14 days and 147 mm in November.
What is the weather like in Osasco in autumn?
In autumn, March through May, Osasco is wet and pleasantly warm. It cools from 27°C by day and 19°C at night in March to 23°C and 14°C in May. Rain eases through the season: 16 rainy days and 160 mm in March, 6 days and 67 mm in May.
How many days a year does it rain in Osasco?
On long-term average, Osasco has about 137 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,404 mm.

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