Itajaí weather in May
In May, Itajaí has daytime highs averaging 22 °C, nights around 17 °C, with 11 wet days, and a sea temperature of 22 °C. Figures are 1991–2020 climate normals.
- 22.1°C Average high
- 17.0°C Average low
- 11days Wet days
- 113mm Rainfall
- 22.1°C Sea temperature
- 11h Daylight
Daily temperatures through May
How May develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 May | 23.0 °C | 17.8 °C | 34 % |
| 11–20 May | 22.2 °C | 17.2 °C | 40 % |
| 21–31 May | 21.3 °C | 16.3 °C | 35 % |
- Average highs fall from 23.0 °C early in May to 21.3 °C by the end of it.
- Rain is most likely over days 11–20 of May (40 % of days) and least likely over days 1–10 (34 %).
What to expect
| Measure | Typical May | Share of the month |
|---|---|---|
| Days above 25 °C | 2.6 of 31 | 8 % |
| Days above 30 °C | 0.03 of 31 | 0 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 11 of 31 | 36 % |
Conditions in May
| Measure | Average |
|---|---|
| Mean temperature | 19 °C |
| Record high (1991–2020) | 30 °C |
| Record low (1991–2020) | 8.5 °C |
| Relative humidity | 82 % |
| Wind speed | 14 km/h |
| Cloud cover | 60 % |
May compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| March | 26.6 °C | 145 mm | 66 % |
| April | 24.9 °C | 98 mm | 61 % |
| May | 22.1 °C | 113 mm | 60 % |
| June | 20.3 °C | 111 mm | 63 % |
| July | 19.4 °C | 98 mm | 62 % |
See all twelve months for Itajaí
- May is the 8th warmest month here.
- It is the 5th driest month of the year.
- It ranks 1st for least cloud cover.
- Days last about 11 hours from sunrise to sunset.
- It rains on 11 of 31 days — 36 % of the month.
- Nights are about 5.1 °C cooler than the middle of the day.
- The hottest May day on record since 1991 reached 30 °C, 8.2 °C above the usual daytime high.
- Beach score: 65 / 100 — see how this is calculated.
QuestionsMay in Itajaí, answered
How warm is Itajaí in May?
Daily highs average 22 °C and nights fall to about 17 °C, a spread of 5.1 °C between afternoon and dawn. That makes May the 8th warmest month of the year here.
Does it rain much in Itajaí in May?
May averages 113 mm of rain, spread over about 11 of the 31 days — 36 % of the month. Cloud cover averages 60 % of the sky.
Is the sea warm enough to swim in May?
The sea averages 22 °C off Itajaí in May. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in May?
Itajaí averages 11 hours between sunrise and sunset in May. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.