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Parnaíba weather by month: averages, rainfall & climate trends

Warmth in Parnaíba is remarkably steady: only 2.1°C separates the warmest month from the coolest, so there is no cold season to speak of. Rainfall is strongly seasonal: the bulk of the year's rain falls between January and May. Parnaíba weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

−4.2°Chigh well below average

30° / 26°Today
35° / 25°Average
see today in detail →

How it's changed

+0.6°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49324days above 30°C a year now (2016–2025) · 282 in the 1940sdays above 30°C · 282 in the 1940s+0.6°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 143 mmhigh 31°low 25°February, rain 190 mmhigh 30°low 24°March, rain 289 mmhigh 30°low 24°April, rain 263 mmhigh 30°low 24°May, rain 168 mmhigh 31°low 24°June, rain 41 mmhigh 32°low 24°July, rain 18 mmhigh 33°low 24°August, rain 4 mmhigh 34°low 24°September, rain 3 mmhigh 35°low 25°October, rain 5 mmhigh 35°low 25°November, rain 10 mmhigh 34°low 25°December, rain 48 mmhigh 33°low 25°wettest month March, 289 mm · 1,181 mm a yearsee month by month →

Right now

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

Right now

27.2°

29°feels like
79%humidity
23°dew point
26 km/hfrom E
UV index0.0
sunrise05:27sunset17:37day length12h 11m
SatMostly clear30°26°
TodayMostly clear30°27°
MonPartly cloudy30°26°
TuePartly cloudy30°26°
WedMostly clear31°26°
ThuMostly clear32°26°
FriClear31°26°

On this date: October 18

Today (forecast)
30° / 26°
Average for October 18
35° / 25°

High well below average · −4.2°C

  • Record high: 36.4° · 1961
  • Record low: 23.5° · 1946
  • One year ago: 35° / 25°

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 Parnaíba is sampled from the ECMWF ERA5 reanalysis at 2.90°S, 41.78°W, with daily records since 1940.

Coordinates
2.90°S, 41.78°W
Time zone
America/Fortaleza
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

17 of the last 31 days were warmer than the historical average for that date. Average difference: −0.1°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 November, at around 34.2°C by mid-afternoon, with nights around 25.0°C. The coolest month is March, when afternoons reach about 29.8°C and overnight lows sit around 24.2°C.

The yearly total for Parnaíba comes to about 1,181 mm; monthly amounts range from 3 mm in September up to 289 mm in March.

The record here starts in 1940, and since then the annual mean in Parnaíba has climbed 0.6°C from the first ten years to the last ten. The last decade has also run wetter, about 9% above the long-term precipitation average.

Climate graph (climograph)

November is the warmest month, March the coolest: a yearly swing of 2°C. Wettest month: March (~289 mm). Whole year averages ~1,181 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).

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.

Parnaíba 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 lowRainDaylightRecord highRecord low
January31.3°24.6°143 mm12.2 h37.5° (2012)22.0° (1973)
February30.3°24.3°190 mm12.1 h37.3° (2012)22.3° (1974)
March29.8°24.2°289 mm12.0 h36.3° (2013)22.1° (1967)
April30.0°24.3°263 mm11.9 h34.3° (1998)22.3° (1976)
May30.7°24.4°168 mm11.9 h36.6° (1958)22.4° (1955)
June31.7°24.3°41 mm11.8 h36.4° (1942)21.3° (2009)
July33.0°24.3°18 mm11.8 h36.6° (1951)20.3° (1974)
August34.3°24.4°4 mm11.9 h37.8° (1958)21.8° (2020)
September34.7°24.6°3 mm12.0 h38.3° (1942)22.7° (2024)
October34.6°24.8°5 mm12.1 h38.1° (2016)22.6° (1959)
November34.2°25.0°10 mm12.1 h37.5° (2016)22.9° (1975)
December33.1°25.1°48 mm12.2 h37.6° (2012)22.7° (1975)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +0.6°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: +0.13°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

Mar–May is warming fastest: +0.18°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: 281.8 early in the record → 324.4 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 1942, all-time low in 1974: 38.3°C / 20.3°C.

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

Annual rainfall

~1,181 mm/year on average. Last decade: +9% vs that average. Long-term trend: +17 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 Parnaíba

Which is the warmest month in Parnaíba?
On long-term average, the warmest month in Parnaíba is November (mean daily temperature of about 28.6°C) and the coolest is March (about 26.5°C).
How does today's temperature in Parnaíba compare to the historical average?
On October 18, 2026, Parnaíba is forecast to reach a high of 30.3°C and a low of 25.5°C. The long-term average for this date (the full record since 1940) is a high of 34.5°C and a low of 24.9°C, so today's high is 4.2°C cooler than that average.
How much has Parnaíba warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Parnaíba is about 0.6°C warmer.
How much does it rain in Parnaíba?
Parnaíba receives about 1,181 mm of precipitation per year on long-term average, with March typically the wettest month.
What is the average temperature in Parnaíba?
Over the full record (since 1940), the annual mean temperature in Parnaíba is about 27.7°C. The warmest month is November and the coolest is March.
What are the average temperatures in Parnaíba by month?
Average daily highs and lows for each month in Parnaíba (°C, full record since 1940): January 31°/25°, February 30°/24°, March 30°/24°, April 30°/24°, May 31°/24°, June 32°/24°, July 33°/24°, August 34°/24°, September 35°/25°, October 35°/25°, November 34°/25°, December 33°/25°.

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