Climate and Average Weather Year Round in Merlo Argentina

In Merlo, the summers are warm, humid, wet, and mostly clear and the winters are cold and partly cloudy. Over the course of the year, the temperature typically varies from 42°F to 87°F and is rarely below 31°F or above 96°F.

Based on the tourism score, the best time of year to visit Merlo for warm-weather activities is from mid October to mid April.

The hot season lasts for 3.4 months, from November 30 to March 9, with an average daily high temperature above 81°F. The hottest month of the year in Merlo is January, with an average high of 86°F and low of 66°F.

The cool season lasts for 3.0 months, from May 22 to August 21, with an average daily high temperature below 64°F. The coldest month of the year in Merlo is July, with an average low of 42°F and high of 59°F.

In Merlo, 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 Merlo begins around September 20 and lasts for 7.1 months, ending around April 24.

The clearest month of the year in Merlo is January, during which on average the sky is clear, mostly clear, or partly cloudy 71% of the time.

The cloudier part of the year begins around April 24 and lasts for 4.9 months, ending around September 20.

The cloudiest month of the year in Merlo is June, during which on average the sky is overcast or mostly cloudy 52% 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 Merlo varies throughout the year.

The wetter season lasts 6.4 months, from October 5 to April 17, with a greater than 27% chance of a given day being a wet day. The month with the most wet days in Merlo is February, with an average of 9.7 days with at least 0.04 inches of precipitation.

The drier season lasts 5.6 months, from April 17 to October 5. The month with the fewest wet days in Merlo is July, with an average of 5.6 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 Merlo is February, with an average of 9.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 37% on February 8.

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. Merlo experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Merlo. The month with the most rain in Merlo is February, with an average rainfall of 4.5 inches.

The month with the least rain in Merlo is July, with an average rainfall of 2.0 inches.

The length of the day in Merlo varies significantly over the course of the year. In 2024, the shortest day is June 20, with 9 hours, 50 minutes of daylight; the longest day is December 21, with 14 hours, 29 minutes of daylight.

The earliest sunrise is at 5:34 AM on December 5, and the latest sunrise is 2 hours, 28 minutes later at 8:02 AM on June 29. The earliest sunset is at 5:50 PM on June 11, and the latest sunset is 2 hours, 21 minutes later at 8:11 PM on January 6.

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

Merlo experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.8 months, from November 18 to April 13, during which time the comfort level is muggy, oppressive, or miserable at least 11% of the time. The month with the most muggy days in Merlo is February, with 11.9 days that are muggy or worse.

The month with the fewest muggy days in Merlo is July, with 0.1 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 Merlo experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 5.4 months, from July 10 to December 24, with average wind speeds of more than 9.2 miles per hour. The windiest month of the year in Merlo is September, with an average hourly wind speed of 9.9 miles per hour.

The calmer time of year lasts for 6.6 months, from December 24 to July 10. The calmest month of the year in Merlo is May, with an average hourly wind speed of 8.6 miles per hour.

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

The wind is most often from the north for 5.1 months, from April 2 to September 5, with a peak percentage of 35% on May 20. The wind is most often from the east for 6.9 months, from September 5 to April 2, with a peak percentage of 42% on January 1.

Merlo 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 significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.7 months, from December 7 to March 29, with an average temperature above 72°F. The month of the year in Merlo with the warmest water is February, with an average temperature of 76°F.

The time of year with cooler water lasts for 3.5 months, from June 4 to September 19, with an average temperature below 59°F. The month of the year in Merlo with the coolest water is July, with an average temperature of 55°F.

To characterize how pleasant the weather is in Merlo 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 Merlo for general outdoor tourist activities is from mid October to mid April, with a peak score in the second week of March.

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 Merlo for hot-weather activities is from mid December to early 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).

The growing season in Merlo typically lasts for 10 months (304 days), from around August 9 to around June 9, rarely starting after September 6, or ending before May 13.

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 Merlo should appear around July 26, only rarely appearing before July 17 or after August 9.

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 3.5 months, from October 30 to February 13, with an average daily incident shortwave energy per square meter above 6.7 kWh. The brightest month of the year in Merlo is December, with an average of 7.8 kWh.

The darker period of the year lasts for 3.5 months, from April 30 to August 14, with an average daily incident shortwave energy per square meter below 3.5 kWh. The darkest month of the year in Merlo is June, with an average of 2.4 kWh.

For the purposes of this report, the geographical coordinates of Merlo are -34.666 deg latitude, -58.729 deg longitude, and 69 ft elevation.

The topography within 2 miles of Merlo contains only modest variations in elevation, with a maximum elevation change of 105 feet and an average elevation above sea level of 65 feet. Within 10 miles also contains only modest variations in elevation (197 feet). Within 50 miles also contains only modest variations in elevation (322 feet).

The area within 2 miles of Merlo is covered by artificial surfaces (47%), shrubs (25%), and trees (13%), within 10 miles by shrubs (28%) and artificial surfaces (22%), and within 50 miles by cropland (36%) and water (19%).