Climate and Average Weather Year Round in Arroio Grande Brazil

In Arroio Grande, the summers are warm and muggy, the winters are cool, and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 46°F to 85°F and is rarely below 36°F or above 93°F.

Based on the tourism score, the best times of year to visit Arroio Grande for warm-weather activities are from late February to late April and from early October to early January.

The hot season lasts for 3.5 months, from December 3 to March 20, with an average daily high temperature above 81°F. The hottest month of the year in Arroio Grande is January, with an average high of 85°F and low of 67°F.

The cool season lasts for 3.4 months, from May 24 to September 5, with an average daily high temperature below 67°F. The coldest month of the year in Arroio Grande is July, with an average low of 47°F and high of 63°F.

In Arroio Grande, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Arroio Grande begins around October 6 and lasts for 6.6 months, ending around April 23.

The clearest month of the year in Arroio Grande is January, during which on average the sky is clear, mostly clear, or partly cloudy 66% of the time.

The cloudier part of the year begins around April 23 and lasts for 5.5 months, ending around October 6.

The cloudiest month of the year in Arroio Grande is June, during which on average the sky is overcast or mostly cloudy 51% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Arroio Grande varies throughout the year.

The wetter season lasts 1.6 months, from January 15 to March 2, with a greater than 32% chance of a given day being a wet day. The month with the most wet days in Arroio Grande is February, with an average of 11.0 days with at least 0.04 inches of precipitation.

The drier season lasts 10 months, from March 2 to January 15. The month with the fewest wet days in Arroio Grande is May, with an average of 8.0 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Arroio Grande is February, with an average of 11.0 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 40% on February 13.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Arroio Grande experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Arroio Grande. The month with the most rain in Arroio Grande is February, with an average rainfall of 4.9 inches.

The month with the least rain in Arroio Grande is December, with an average rainfall of 3.3 inches.

The length of the day in Arroio Grande varies significantly over the course of the year. In 2024, the shortest day is June 20, with 10 hours, 2 minutes of daylight; the longest day is December 21, with 14 hours, 16 minutes of daylight.

The earliest sunrise is at 5:18 AM on December 4, and the latest sunrise is 2 hours, 16 minutes later at 7:34 AM on June 30. The earliest sunset is at 5:34 PM on June 10, and the latest sunset is 2 hours, 9 minutes later at 7:43 PM on January 9.

Daylight saving time (DST) is not observed in Arroio Grande during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Arroio Grande experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 6.0 months, from October 24 to April 26, during which time the comfort level is muggy, oppressive, or miserable at least 17% of the time. The month with the most muggy days in Arroio Grande is February, with 18.3 days that are muggy or worse.

The month with the fewest muggy days in Arroio Grande is July, with 0.5 days that are muggy or worse.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Arroio Grande experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.4 months, from August 19 to March 1, with average wind speeds of more than 9.1 miles per hour. The windiest month of the year in Arroio Grande is December, with an average hourly wind speed of 10.0 miles per hour.

The calmer time of year lasts for 5.6 months, from March 1 to August 19. The calmest month of the year in Arroio Grande is May, with an average hourly wind speed of 8.3 miles per hour.

The predominant average hourly wind direction in Arroio Grande varies throughout the year.

The wind is most often from the west for 2.1 months, from May 9 to July 12, with a peak percentage of 33% on June 14. The wind is most often from the north for 4.3 weeks, from July 12 to August 11, with a peak percentage of 29% on July 13. The wind is most often from the east for 8.9 months, from August 11 to May 9, with a peak percentage of 53% on January 1.

Arroio Grande is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.7 months, from December 17 to April 9, with an average temperature above 72°F. The month of the year in Arroio Grande with the warmest water is February, with an average temperature of 75°F.

The time of year with cooler water lasts for 3.5 months, from June 13 to September 27, with an average temperature below 60°F. The month of the year in Arroio Grande with the coolest water is July, with an average temperature of 57°F.

To characterize how pleasant the weather is in Arroio Grande throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Arroio Grande for general outdoor tourist activities are from late February to late April and from early October to early January, with a peak score in the last week of November.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Arroio Grande for hot-weather activities is from early December to mid March, with a peak score in the second week of January.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

While it does not do so every year, freezing temperatures are seen in Arroio Grande over some winters. The day least likely to be in the growing season is July 9, with a 67% chance.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Arroio Grande should appear around July 17, only rarely appearing before July 12 or after July 26.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.1 months, from November 3 to February 6, with an average daily incident shortwave energy per square meter above 6.7 kWh. The brightest month of the year in Arroio Grande is December, with an average of 7.6 kWh.

The darker period of the year lasts for 3.5 months, from May 1 to August 16, with an average daily incident shortwave energy per square meter below 3.6 kWh. The darkest month of the year in Arroio Grande is June, with an average of 2.7 kWh.

For the purposes of this report, the geographical coordinates of Arroio Grande are -32.237 deg latitude, -53.087 deg longitude, and 102 ft elevation.

The topography within 2 miles of Arroio Grande contains only modest variations in elevation, with a maximum elevation change of 210 feet and an average elevation above sea level of 108 feet. Within 10 miles contains only modest variations in elevation (725 feet). Within 50 miles contains significant variations in elevation (1,621 feet).

The area within 2 miles of Arroio Grande is covered by trees (31%), cropland (24%), grassland (23%), and shrubs (19%), within 10 miles by trees (32%) and cropland (31%), and within 50 miles by grassland (25%) and trees (22%).