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Guarulhos weather by month: averages, rainfall & climate trends

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

Today vs average

−0.1°Chigh near average

25° / 14°Today
25° / 16°Average
see today in detail →

How it's changed

+1.4°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4950days above 30°C a year now (2016–2025) · 5 in the 1940sdays above 30°C · 5 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 226 mmhigh 27°low 19°February, rain 197 mmhigh 27°low 19°March, rain 171 mmhigh 26°low 19°April, rain 83 mmhigh 25°low 17°May, rain 72 mmhigh 23°low 14°June, rain 54 mmhigh 22°low 13°July, rain 53 mmhigh 22°low 12°August, rain 48 mmhigh 23°low 13°September, rain 93 mmhigh 24°low 15°October, rain 141 mmhigh 25°low 16°November, rain 156 mmhigh 25°low 17°December, rain 215 mmhigh 26°low 18°wettest month January, 226 mm · 1,510 mm a yearsee month by month →

Right now

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

Right now

22.3°

21°feels like
44%humidity
10°dew point
7 km/hfrom SW
UV index0.2
sunrise05:30sunset18:12day length12h 42m
TodayPartly cloudy25°14°
MonPartly cloudy23°14°
TuePartly cloudy23°13°
WedOvercast24°14°
ThuOvercast23°17°
FriOvercast22°17°
SatOvercast24°19°

On this date: October 18

Today (forecast)
25° / 14°
Average for October 18
25° / 16°

High near average · −0.1°C

  • Record high: 33.0° · 1963
  • Record low: 10.1° · 1955
  • One year ago: 24° / 19°

Every October 18 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 18 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 Guarulhos is sampled from the ECMWF ERA5 reanalysis at 23.46°S, 46.53°W, with daily records since 1940.

Coordinates
23.46°S, 46.53°W
Time zone
America/Sao Paulo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

21 of the last 31 days were warmer than the historical average for that date. Average difference: +1.0°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 27.1°C by mid-afternoon, with nights around 19.2°C. Around 60 nights a year stay above 20°C. The coolest month is July, when afternoons reach about 21.7°C and overnight lows sit around 12.3°C.

The yearly total for Guarulhos comes to about 1,510 mm; monthly amounts range from 48 mm in August up to 226 mm in January. A typical year brings rain or snow on around 144 days.

Over the full record (since 1940), the annual mean temperature in Guarulhos has risen by 1.4°C between its first decade and its last. Days above 30°C have grown noticeably more frequent, from around 5 a year in the first decade to about 50 in the last.

Climate graph (climograph)

February is the warmest month, July the coolest: a yearly swing of 6°C. Wettest month: January (~226 mm). Whole year averages ~1,510 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 144 rainy days a year: most in January (~21), fewest in July (~5).

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.

Guarulhos 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. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightRecord highRecord low
January26.8°19.1°226 mm2113.3 h34.3° (2006)12.0° (1943)
February27.1°19.2°197 mm1912.8 h34.5° (2014)12.8° (1991)
March26.3°18.5°171 mm1712.2 h33.2° (2012)11.9° (1961)
April24.7°16.7°83 mm911.4 h32.2° (1996)6.1° (1971)
May22.6°14.4°72 mm710.9 h31.3° (2024)4.3° (1979)
June21.7°13.0°54 mm510.6 h28.9° (2010)2.4° (1979)
July21.7°12.3°53 mm510.7 h29.6° (1983)2.1° (2021)
August23.3°13.2°48 mm511.2 h33.4° (2005)3.1° (1984)
September24.3°14.7°93 mm811.9 h36.9° (1961)5.4° (2006)
October24.6°16.2°141 mm1412.6 h36.4° (2020)7.6° (1974)
November25.0°16.9°156 mm1513.2 h36.5° (2023)9.2° (1970)
December25.9°18.2°215 mm2013.4 h34.2° (2023)11.2° (1945)

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: +0.26°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: 5.0 early in the record → 50.2 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

All-time high in 1961, all-time low in 2021: 36.9°C / 2.1°C.

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

Annual rainfall

~1,510 mm/year on average. Last decade: −13% vs that average. Long-term trend: −37 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 Guarulhos

Which is the warmest month in Guarulhos?
On long-term average, the warmest month in Guarulhos is February (mean daily temperature of about 22.5°C) and the coolest is July (about 16.4°C).
How does today's temperature in Guarulhos compare to the historical average?
On October 18, 2026, Guarulhos is forecast to reach a high of 24.5°C and a low of 14.4°C. The long-term average for this date (the full record since 1940) is a high of 24.6°C and a low of 16.5°C, so today's high is about equal to that average.
How much has Guarulhos warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Guarulhos is about 1.4°C warmer.
How much does it rain in Guarulhos?
Guarulhos receives about 1,510 mm of precipitation per year on long-term average, with January typically the wettest month.
What is the average temperature in Guarulhos?
Over the full record (since 1940), the annual mean temperature in Guarulhos is about 19.6°C. The warmest month is February and the coolest is July.
What are the average temperatures in Guarulhos by month?
Average daily highs and lows for each month in Guarulhos (°C, full record since 1940): January 27°/19°, February 27°/19°, March 26°/19°, April 25°/17°, May 23°/14°, June 22°/13°, July 22°/12°, August 23°/13°, September 24°/15°, October 25°/16°, November 25°/17°, December 26°/18°.
What is the weather like in Guarulhos in summer?
Summer in Guarulhos (December to February) is wet and warm. Daytime highs sit at 26–27°C and nights at 18–19°C; February is the warmest month. Rain falls on about 20 days a month, adding up to around 213 mm. No season is wetter.
What is the weather like in Guarulhos in winter?
Winter in Guarulhos (June to August) is pleasantly warm. Afternoons run 22–23°C and nights 12–13°C; July is the coldest month. Rain is steady at around 52 mm a month, spread over roughly 5 days. No season is drier.
What is the weather like in Guarulhos in spring?
In spring, September through November, Guarulhos is wet and pleasantly warm. Expect 24–25°C by day and 15–17°C at night, with November the warmest month. Rain rises from 93 mm on 8 days in September to 156 mm on 15 days in November.
What is the weather like in Guarulhos in autumn?
Autumn in Guarulhos (March to May) is wet and pleasantly warm. Daytime highs sit at 23–26°C and nights at 14–19°C; May is the coldest month. Rain falls off from 171 mm on 17 days in March to 72 mm on 7 days in May.
How many days a year does it rain in Guarulhos?
On long-term average, Guarulhos has about 144 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,510 mm.

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