Climate and Average Weather Year Round in Ascensión Bolivia

In Ascensión, the summers are short, hot, and humid; the winters are short, warm, and muggy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 65°F to 94°F and is rarely below 56°F or above 102°F.

Based on the beach/pool score, the best time of year to visit Ascensión for hot-weather activities is from mid April to mid September.

The hot season lasts for 2.4 months, from August 21 to November 2, with an average daily high temperature above 92°F. The hottest month of the year in Ascensión is October, with an average high of 93°F and low of 74°F.

The cool season lasts for 2.8 months, from April 17 to July 12, with an average daily high temperature below 86°F. The coldest month of the year in Ascensión is June, with an average low of 66°F and high of 85°F.

In Ascensión, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.

The clearer part of the year in Ascensión begins around May 4 and lasts for 5.1 months, ending around October 9.

The clearest month of the year in Ascensión is August, during which on average the sky is clear, mostly clear, or partly cloudy 70% of the time.

The cloudier part of the year begins around October 9 and lasts for 6.9 months, ending around May 4.

The cloudiest month of the year in Ascensión is February, during which on average the sky is overcast or mostly cloudy 82% 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 Ascensión varies very significantly throughout the year.

The wetter season lasts 5.5 months, from October 21 to April 7, with a greater than 36% chance of a given day being a wet day. The month with the most wet days in Ascensión is January, with an average of 18.7 days with at least 0.04 inches of precipitation.

The drier season lasts 6.5 months, from April 7 to October 21. The month with the fewest wet days in Ascensión is July, with an average of 3.3 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 Ascensión is January, with an average of 18.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 62% on February 14.

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. Ascensión experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Ascensión. The month with the most rain in Ascensión is January, with an average rainfall of 7.5 inches.

The month with the least rain in Ascensión is July, with an average rainfall of 1.1 inches.

The length of the day in Ascensión varies over the course of the year. In 2024, the shortest day is June 20, with 11 hours, 12 minutes of daylight; the longest day is December 21, with 13 hours, 4 minutes of daylight.

The earliest sunrise is at 5:31 AM on November 22, and the latest sunrise is 1 hour, 9 minutes later at 6:40 AM on July 9. The earliest sunset is at 5:47 PM on June 1, and the latest sunset is 1 hour, 3 minutes later at 6:50 PM on January 21.

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

Ascensión experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 9.3 months, from September 18 to June 27, during which time the comfort level is muggy, oppressive, or miserable at least 34% of the time. The month with the most muggy days in Ascensión is January, with 30.4 days that are muggy or worse.

The month with the fewest muggy days in Ascensión is August, with 5.2 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 Ascensión does not vary significantly over the course of the year, remaining within 0.5 miles per hour of 2.6 miles per hour throughout.

The predominant average hourly wind direction in Ascensión is from the north throughout the year.

To characterize how pleasant the weather is in Ascensión 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 Ascensión for general outdoor tourist activities is from late May to late August, with a peak score in the third week of July.

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 Ascensión for hot-weather activities is from mid April to mid September, with a peak score in the second week of August.

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).

Temperatures in Ascensión are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

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.

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 some seasonal variation over the course of the year.

The brighter period of the year lasts for 4.0 months, from October 14 to February 13, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest month of the year in Ascensión is November, with an average of 6.2 kWh.

The darker period of the year lasts for 2.3 months, from May 8 to July 16, with an average daily incident shortwave energy per square meter below 5.0 kWh. The darkest month of the year in Ascensión is June, with an average of 4.7 kWh.

For the purposes of this report, the geographical coordinates of Ascensión are -15.700 deg latitude, -63.083 deg longitude, and 650 ft elevation.

The topography within 2 miles of Ascensión contains only modest variations in elevation, with a maximum elevation change of 174 feet and an average elevation above sea level of 701 feet. Within 10 miles contains only modest variations in elevation (653 feet). Within 50 miles contains significant variations in elevation (2,320 feet).

The area within 2 miles of Ascensión is covered by trees (84%), within 10 miles by trees (83%), and within 50 miles by trees (91%).