Climate and Average Weather Year Round in Al Ma‘allā’ Yemen

In Al Ma‘allā’, the summers are long, hot, oppressive, and mostly cloudy; the winters are long, warm, muggy, windy, and mostly clear; and it is dry year round. Over the course of the year, the temperature typically varies from 75°F to 95°F and is rarely below 73°F or above 98°F.

Based on the beach/pool score, the best time of year to visit Al Ma‘allā’ for hot-weather activities is from late October to late March.

The hot season lasts for 4.0 months, from May 20 to September 21, with an average daily high temperature above 93°F. The hottest month of the year in Al Ma‘allā’ is June, with an average high of 95°F and low of 86°F.

The cool season lasts for 3.7 months, from November 26 to March 17, with an average daily high temperature below 84°F. The coldest month of the year in Al Ma‘allā’ is January, with an average low of 75°F and high of 82°F.

In Al Ma‘allā’, 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 Al Ma‘allā’ begins around September 24 and lasts for 7.0 months, ending around April 25.

The clearest month of the year in Al Ma‘allā’ is November, during which on average the sky is clear, mostly clear, or partly cloudy 75% of the time.

The cloudier part of the year begins around April 25 and lasts for 5.0 months, ending around September 24.

The cloudiest month of the year in Al Ma‘allā’ is June, during which on average the sky is overcast or mostly cloudy 74% of the time.

Al Ma‘allā’ 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 1% to 10%, with an average value of 5%.

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 Al Ma‘allā’ is August, with an average of 2.6 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 10% on September 7.

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. Al Ma‘allā’ experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 1.2 months, from August 8 to September 16, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Al Ma‘allā’ is August, with an average rainfall of 0.6 inches.

The rainless period of the year lasts for 11 months, from September 16 to August 8. The month with the least rain in Al Ma‘allā’ is December, with an average rainfall of 0.1 inches.

The length of the day in Al Ma‘allā’ does not vary substantially over the course of the year, staying within 52 minutes of 12 hours throughout. In 2024, the shortest day is December 21, with 11 hours, 23 minutes of daylight; the longest day is June 20, with 12 hours, 53 minutes of daylight.

The earliest sunrise is at 5:32 AM on June 1, and the latest sunrise is 54 minutes later at 6:26 AM on January 24. The earliest sunset is at 5:30 PM on November 19, and the latest sunset is 1 hour, 0 minutes later at 6:30 PM on July 8.

Daylight saving time (DST) is not observed in Al Ma‘allā’ 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.

Al Ma‘allā’ experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 10 months, from February 8 to December 19, during which time the comfort level is muggy, oppressive, or miserable at least 74% of the time. The month with the most muggy days in Al Ma‘allā’ is May, with 30.7 days that are muggy or worse.

The month with the fewest muggy days in Al Ma‘allā’ is January, with 21.2 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 Al Ma‘allā’ experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.5 months, from October 12 to April 27, with average wind speeds of more than 9.9 miles per hour. The windiest month of the year in Al Ma‘allā’ is January, with an average hourly wind speed of 12.9 miles per hour.

The calmer time of year lasts for 5.5 months, from April 27 to October 12. The calmest month of the year in Al Ma‘allā’ is September, with an average hourly wind speed of 7.5 miles per hour.

The predominant average hourly wind direction in Al Ma‘allā’ varies throughout the year.

The wind is most often from the south for 1.4 months, from May 29 to July 11 and for 1.0 months, from August 14 to September 14, with a peak percentage of 54% on June 22. The wind is most often from the west for 1.1 months, from July 11 to August 14, with a peak percentage of 55% on July 26. The wind is most often from the east for 8.5 months, from September 14 to May 29, with a peak percentage of 98% on January 1.

Al Ma‘allā’ 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 1.9 months, from May 8 to July 4, with an average temperature above 85°F. The month of the year in Al Ma‘allā’ with the warmest water is June, with an average temperature of 86°F.

The time of year with cooler water lasts for 3.4 months, from December 6 to March 19, with an average temperature below 80°F. The month of the year in Al Ma‘allā’ with the coolest water is February, with an average temperature of 78°F.

To characterize how pleasant the weather is in Al Ma‘allā’ 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 Al Ma‘allā’ for general outdoor tourist activities is from early December to late February, with a peak score in the second 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 Al Ma‘allā’ for hot-weather activities is from late October to late March, with a peak score in the last week of November.

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 Al Ma‘allā’ 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 2.1 months, from February 24 to April 26, with an average daily incident shortwave energy per square meter above 6.7 kWh. The brightest month of the year in Al Ma‘allā’ is March, with an average of 7.1 kWh.

The darker period of the year lasts for 3.7 months, from May 26 to September 17, with an average daily incident shortwave energy per square meter below 5.4 kWh. The darkest month of the year in Al Ma‘allā’ is July, with an average of 5.0 kWh.

For the purposes of this report, the geographical coordinates of Al Ma‘allā’ are 12.790 deg latitude, 45.002 deg longitude, and 43 ft elevation.

The topography within 2 miles of Al Ma‘allā’ contains very significant variations in elevation, with a maximum elevation change of 1,699 feet and an average elevation above sea level of 184 feet. Within 10 miles also contains very significant variations in elevation (1,854 feet). Within 50 miles contains very significant variations in elevation (6,237 feet).

The area within 2 miles of Al Ma‘allā’ is covered by bare soil (52%), water (38%), and artificial surfaces (11%), within 10 miles by water (67%) and bare soil (17%), and within 50 miles by water (63%) and bare soil (26%).