Climate and Average Weather Year Round in Trelew Argentina

In Trelew, the summers are warm and mostly clear, the winters are cold and partly cloudy, and it is dry and windy year round. Over the course of the year, the temperature typically varies from 35°F to 83°F and is rarely below 25°F or above 94°F.

Based on the tourism score, the best time of year to visit Trelew for warm-weather activities is from mid November to mid March.

The warm season lasts for 3.6 months, from November 24 to March 11, with an average daily high temperature above 77°F. The hottest month of the year in Trelew is January, with an average high of 83°F and low of 59°F.

The cool season lasts for 3.1 months, from May 18 to August 21, with an average daily high temperature below 59°F. The coldest month of the year in Trelew is July, with an average low of 35°F and high of 54°F.

In Trelew, 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 Trelew begins around October 10 and lasts for 6.1 months, ending around April 13.

The clearest month of the year in Trelew is January, during which on average the sky is clear, mostly clear, or partly cloudy 72% of the time.

The cloudier part of the year begins around April 13 and lasts for 5.9 months, ending around October 10.

The cloudiest month of the year in Trelew is May, during which on average the sky is overcast or mostly cloudy 49% of the time.

Trelew does not experience significant seasonal variation in the frequency of wet days (i.e., those with greater than 0.04 inches of liquid or liquid-equivalent precipitation). The frequency ranges from 5% to 11%, with an average value of 8%.

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 Trelew is May, with an average of 3.1 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 10% on May 20.

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. Trelew experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 8.9 months, from January 26 to October 22, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Trelew is April, with an average rainfall of 0.9 inches.

The rainless period of the year lasts for 3.1 months, from October 22 to January 26. The month with the least rain in Trelew is December, with an average rainfall of 0.4 inches.

The length of the day in Trelew varies significantly over the course of the year. In 2024, the shortest day is June 20, with 8 hours, 58 minutes of daylight; the longest day is December 21, with 15 hours, 24 minutes of daylight.

The earliest sunrise is at 5:34 AM on December 9, and the latest sunrise is 3 hours, 20 minutes later at 8:54 AM on June 27. The earliest sunset is at 5:51 PM on June 13, and the latest sunset is 3 hours, 13 minutes later at 9:04 PM on January 2.

Daylight saving time (DST) is not observed in Trelew 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.

The perceived humidity level in Trelew, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

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 Trelew experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 3.9 months, from October 28 to February 23, with average wind speeds of more than 13.7 miles per hour. The windiest month of the year in Trelew is December, with an average hourly wind speed of 14.4 miles per hour.

The calmer time of year lasts for 8.1 months, from February 23 to October 28. The calmest month of the year in Trelew is September, with an average hourly wind speed of 13.0 miles per hour.

The predominant average hourly wind direction in Trelew is from the west throughout the year.

Trelew 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 3.4 months, from December 25 to April 7, with an average temperature above 60°F. The month of the year in Trelew with the warmest water is February, with an average temperature of 62°F.

The time of year with cooler water lasts for 3.6 months, from June 30 to October 18, with an average temperature below 51°F. The month of the year in Trelew with the coolest water is August, with an average temperature of 48°F.

To characterize how pleasant the weather is in Trelew 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 time of year to visit Trelew for general outdoor tourist activities is from mid November to mid March, with a peak score in the third week of January.

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 Trelew for hot-weather activities is from late December to early February, 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).

The growing season in Trelew typically lasts for 7.7 months (232 days), from around September 23 to around May 13, rarely starting before August 30 or after October 18, and rarely ending before April 19 or after June 3.

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 Trelew should appear around August 23, only rarely appearing before August 9 or after September 7.

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 3.2 months, from November 4 to February 10, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest month of the year in Trelew is December, with an average of 8.4 kWh.

The darker period of the year lasts for 3.9 months, from April 24 to August 21, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest month of the year in Trelew is June, with an average of 1.6 kWh.

For the purposes of this report, the geographical coordinates of Trelew are -43.249 deg latitude, -65.305 deg longitude, and 46 ft elevation.

The topography within 2 miles of Trelew contains only modest variations in elevation, with a maximum elevation change of 121 feet and an average elevation above sea level of 68 feet. Within 10 miles contains only modest variations in elevation (682 feet). Within 50 miles contains significant variations in elevation (1,129 feet).

The area within 2 miles of Trelew is covered by bare soil (54%), trees (17%), and grassland (15%), within 10 miles by trees (28%) and grassland (26%), and within 50 miles by water (31%) and trees (26%).