Climate averages 1991–2020

Guaíba weather
in May.

A mild, wet month: the 9th warmest and the 2nd driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 21.1°C Daytime mean, May
Average low 13.3°C Night-time mean, May
Rainfall 107 mm 9 days with ≥1 mm
Daylight 11 h Sunrise to sunset, per day
Every month in Guaíba · average highYear overview

May is a mild month in Guaíba: daytime highs average 21.1°C and nights cool to about 13.3°C. By daytime temperature it is the 9th warmest of the 12 months.

Expect about 107 mm of rain on roughly 9 days, which makes May a wet month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 38 min on an average May day.

The nearest other city in this atlas is Porto Alegre (13 km away). In May its highs average 21.1°C, about as warm as Guaíba, with 107 mm of rain.

Among the 448 cities listed in Brazil, Guaíba ranks joint 400th of 448 for the warmest May highs and joint 323rd of 448 for the driest May (rainfall, lowest first). The mean May high of those 448 cities is 25.3°C; Guaíba is 4.2°C cooler than that mean.

From May to June, average highs fall by 2.2°C to 18.9°C, and monthly rainfall rises from 107 mm to 113 mm.

The annual picture

May in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. 5101520253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 2000

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Guaíba climate table

1991–2020
Monthly climate averages for Guaíba, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 29.2°C20.8°C20.8°C13714.013.814 h
February 28.8°C20.9°C20.9°C12813.513.213 h
March 27.6°C19.6°C19.6°C11111.912.312 h
April 24.9°C16.7°C16.7°C1069.211.411 h
May, selected 21.1°C13.3°C13.3°C1079.210.611 h
June 18.9°C10.9°C10.9°C1139.210.210 h
July 18.3°C9.9°C9.9°C14010.010.410 h
August 20.4°C11.0°C11.0°C12010.211.011 h
September 21.4°C12.8°C12.8°C14611.111.912 h
October 23.7°C15.2°C15.2°C17012.412.813 h
November 25.9°C16.9°C16.9°C12210.913.614 h
December 28.4°C19.3°C19.3°C12411.814.014 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

May in nearby cities

Distance from Guaíba

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Guaíba) is explained once on the Guaíba year overview and on the Sources, method and limits page.

Porto Alegre and Canoas lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.