Climate and Average Weather Year Round in Şanā’ Yemen

In Şanā’, the summers are long, sweltering, arid, and mostly cloudy and the winters are short, comfortable, dry, and mostly clear. Over the course of the year, the temperature typically varies from 51°F to 101°F and is rarely below 45°F or above 104°F.

Based on the beach/pool score, the best times of year to visit Şanā’ for hot-weather activities are from late March to mid May and from early September to mid October.

The hot season lasts for 4.4 months, from May 6 to September 18, with an average daily high temperature above 97°F. The hottest month of the year in Şanā’ is July, with an average high of 101°F and low of 76°F.

The cool season lasts for 2.6 months, from November 15 to February 5, with an average daily high temperature below 85°F. The coldest month of the year in Şanā’ is December, with an average low of 52°F and high of 82°F.

In Şanā’, 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 Şanā’ begins around August 26 and lasts for 8.4 months, ending around May 6.

The clearest month of the year in Şanā’ is November, during which on average the sky is clear, mostly clear, or partly cloudy 81% of the time.

The cloudier part of the year begins around May 6 and lasts for 3.6 months, ending around August 26.

The cloudiest month of the year in Şanā’ is June, during which on average the sky is overcast or mostly cloudy 66% of the time.

Şanā’ 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 0% to 2%, with an average value of 1%.

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 Şanā’ is February, with an average of 0.6 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 2% on April 9.

Rainfall

The sliding 31-day quantity of rainfall in Şanā’ does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.

The length of the day in Şanā’ varies over the course of the year. In 2024, the shortest day is December 21, with 11 hours, 13 minutes of daylight; the longest day is June 20, with 13 hours, 3 minutes of daylight.

The earliest sunrise is at 5:17 AM on June 2, and the latest sunrise is 1 hour, 2 minutes later at 6:19 AM on January 23. The earliest sunset is at 5:15 PM on November 21, and the latest sunset is 1 hour, 8 minutes later at 6:23 PM on July 8.

Daylight saving time (DST) is not observed in Şanā’ 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 Şanā’, 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, staying within 1% of 1% 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 Şanā’ experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 1.6 months, from July 4 to August 25, with average wind speeds of more than 8.2 miles per hour. The windiest month of the year in Şanā’ is March, with an average hourly wind speed of 9.2 miles per hour.

The calmer time of year lasts for 10 months, from August 25 to July 4. The calmest month of the year in Şanā’ is December, with an average hourly wind speed of 6.8 miles per hour.

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

The wind is most often from the south for 8.1 months, from January 14 to September 17, with a peak percentage of 72% on March 27. The wind is most often from the east for 3.9 months, from September 17 to January 14, with a peak percentage of 48% on January 1.

To characterize how pleasant the weather is in Şanā’ 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 Şanā’ for general outdoor tourist activities are from early January to early March and from mid October to early January, with a peak score in the third 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 times of year to visit Şanā’ for hot-weather activities are from late March to mid May and from early September to mid October, with a peak score in the last week of September.

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 Şanā’ 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 2.7 months, from March 11 to June 1, with an average daily incident shortwave energy per square meter above 7.4 kWh. The brightest month of the year in Şanā’ is April, with an average of 7.7 kWh.

The darker period of the year lasts for 2.2 months, from November 17 to January 24, with an average daily incident shortwave energy per square meter below 6.3 kWh. The darkest month of the year in Şanā’ is December, with an average of 5.9 kWh.

For the purposes of this report, the geographical coordinates of Şanā’ are 15.400 deg latitude, 47.767 deg longitude, and 2,940 ft elevation.

The topography within 2 miles of Şanā’ contains very significant variations in elevation, with a maximum elevation change of 1,490 feet and an average elevation above sea level of 3,379 feet. Within 10 miles contains very significant variations in elevation (2,054 feet). Within 50 miles contains large variations in elevation (3,602 feet).

The area within 2 miles of Şanā’ is covered by bare soil (42%), water (33%), and sparse vegetation (24%), within 10 miles by bare soil (57%) and sparse vegetation (33%), and within 50 miles by bare soil (69%) and sparse vegetation (23%).