WEATHER AND CLIMATE IN YEMEN • GEOGRAPHY AND CLIMATE OF YEMEN Because of the variations in its topography, Yemen has various • climates. In the desert, summers are very hot, while in the mountains the climate is much milder. The surrounding seas bring moist air which results in sufficient rains for Yemen to be the most fertile region in the Arabian peninsula Temperatures are generally very high in Yemen, particularly in the coastal regions. Rainfall is limited, with variations based on elevation. The highlands enjoy a temperate, rainy summer with an average high temperature of 21 °C (69.8 °F) and a cool, moderately dry winter with temperatures occasionally dipping below 0 °C (32.0 °F). The climate of the Tihamah (western coastal plain) is tropical; temperatures occasionally exceed 54 °C (129.2 °F), and the humidity ranges from 50 to 70 percent. Rainfall, which comes in irregular heavy torrents, averages 130 millimeters (5.12 in) annually. In Aden the average temperature is 25 °C (77.0 °F) in January and 32 °C (89.6 °F) in June, but with highs often exceeding 37 °C (98.6 °F). Average annual rainfall is 127 millimeters (5 in). The highest mountainous areas of southern Yemen receive from 520 to 760 mm (20.5 to 29.9 in) of rain a year. Some areas of the western highlands, most notably Ibb and Ta'izz, receive from about 1,000–1,500 millimeters (39.4–59.1 in) of rain each year. The capital, Sana'a, receives around 300 mm (11.8 in) a year, it is not uncommon for the northern and eastern sections of the country to receive no rain for five years or more. The Wadi Hadhramaut in the eastern part of Yemen is arid and hot, and the humidity ranges from 35 percent in June to 64 percent in .January. Yemen is dry in the east and humid in the west. TOPOGRAPHY Topography : Yemen is • characterized by diversity of its surface and therefore has been divided into five major geographic regions are: 1- THE COASTAL PLAINS * The Coastal Plains : extend sporadically along the coast of Yemen, where • mountains and hills cut to reach directly into the sea in more than one place, therefore, the territory of the coastal plain of Yemen on the plains include the following: (Tihama plain – Tuban plain- - Mayfa'a Ahwar plain – Plain, the eastern coastal province, located within al-Mahara). The Coastal Plain region is characterized by a hot climate throughout the year with little rainfalls ranging between 50-100 mm per year, but it is considered an important agricultural region, especially the Tihama Plain due to the large valleys that penetrate this region and into which the floods caused by rainfall on the highlands. • REGION * The Mountain Highlands Region: to the Gulf of Aden and • resulted in the Highlands, including Popup confined basins or mountain called Qiena fields, and mountains of this region is among the highest in the Arabian Peninsula, where it exceeds the average height in 2000, and go up to peaks of more than 3500 m, reaching the highest peak 3666 m in Mount Prophet Shuaib. The line is the division of water in these mountains where the water descends through a number of valleys east and west and south, most important of these valleys: the valley of Moore - abeed - - Rimah - and Wadi Rasyan. The water of these wadis to the Red Sea. valleys draining into the Gulf of Aden and the Arabian Sea: Valley Tuban, and bana and Wadi • Wadi Hadramout. Mountainous Basins Region: This region in the plains and basins in the mountainous highlands, mostly located in the eastern part of the water division line extending from the far north to the far south, including: Dhamar, Mabar, Sana'a Basin, Amran and Saada. • 3- PLATEAU AREAS REGION: * Plateau Areas Region: : This region covers the • eastern half of the country. Elevations decrease from 1, 200-1 ,800 m at the major watershed lines to 900 m on the northern desert border and to sea level on the coast. The climate in general is hot and dry, with average annual rainfall below 100 mm, except in the higher parts. Nevertheless, floods following rare rainfall may be devastating 4- THE DESERT * The Desert : Between the Yemen Mountain • Massif and the Eastern Plateau lies the Ramlat as Sabatayn, a sand desert. Rainfall and vegetation are nearly absent, except along its margins where rivers bring water from adjacent mountain and upland zones. In the north lies the Rub Al Khali desert, which extends far into Saudi Arabia and is approximately 500 000 km² in area. This sand desert is one of the most desolate parts of the world 5- THE ISLANDS * The Islands: spread in the territorial waters of Yemen, Socotra Island is considered the largest island in this archipelago, which includes the addition to the island of Socotra Islands of Samaha and to study and Abdul Kori Socotra is characterized by abundant biodiversity of Socotra it contains about 680 plant species and rare birds and animals . many islands and its topography, climate and environment for most of these islands lie in the Red Sea including: Kamaran which is the largest inhabited island in the Red Sea, the islands of the Hanish archipelago, the island of Meon has a strategic location in the Strait of Bab al-Mandab the southern gate of the Red Sea is the most important islands in the Arabian Sea: Socotra Archipelago. • • THE CLIMATE IN YEMEN Yemen overlooks two seas: the Red Sea, Arabian Sea, Yemen's climate did not benefit from the marine characteristics significantly only in raising the air humidity on the coast, where the impact of these two seas in modifying the properties of the republic's climate is very limited only to humidity and modifying some properties of wind While their role in the instability of air is limited. The amount of rainfall in Yemen in two seasons: the first season during the spring (March-April), and the second season in the summer (July-August), a wetter season of spring. The amount of rainfall varies over Yemen rainfall in Ibb - Taiz and Ad Dali and Yarim range between 600-1500 mm per year and less rainfall in the western coastal plain as it is in Hodeidah, Mokha. Average annual rainfall increases with height of 50 mm on the coast to about 1000 mm on the slopes of the mountains of facing the Red Sea. • In the southern and eastern coasts of the country's western coast average annual rainfall is estimated at about 50 mm per year in Aden, Alfayoush, code and Rayyan. The climate is characterized by high temperatures in summer, up to 42 m and goes down in winter to 25 Degrees, while temperatures gradually drop as we ascend toward higher elevations reaching on average about 33 m as a maximum and to 20 m as a minimum. In winter the minimum temperatures on the highlands go down as low as zero degrees, in the winter of 1986, the temperature in Dhamar went as low as low (- 12 m). • The humidity is high in the coastal plains up to more than 80%, while it goes down toward the inside and reaches its lowest levels in the desert areas with only15% humidity. • • Yemen is roughly rectangular, stretching 1,500 kilometers7 from east to west and 350 kilometers from north to south, and covers an area of 528,000 square kilometers Yemen has several climates. Western Yemen benefits from monsoon rains, which fall mainly in late spring and at the end of summer. Most of the rain falls in the mountains, with an annual maximum of a 1,000 millimeters in the southern mountains, decreasing gradually to an average of 400 millimeters in the northern mountains. Temperatures in the mountains vary with altitude and season, with an average of 16°C and frosty winter nights in the higher mountains. The Tihama coastal strip, by contrast, is always hot and is very humid during the rainy season, a climate similar to that across the Red Sea, in Eritrea and Somalia. The eastern desert has a dry climate, with heavy but sporadic rains and frosty nights. CLIMATIC DATA AND HISTORICAL TEMPERATURES Coastal Plains Historical temperatures at Al Hudaydah city are shown below to illustrate the Coastal Plains typical temperatures experienced in this region Hudaydah • Average Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 80 81 83 86 91 93 94 93 92 89 84 81 Average High Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 82 83 86 89 93 95 95 95 94 91 86 83 Average Low Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 78 78 80 83 88 90 92 90 90 87 81 78 Highest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 90 90 91 102 102 104 101 102 100 100 100 90 Lowest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. 50 43 50 48 56 57 66 65 60 57 49 28 • WESTERN SLOPES Ta'izz is a typical town on the Western Slopes. Its historical temperatures give an insight into suitable conditions in which to keep Calyptratus. Average Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 63 67 72 76 78 80 80 78 76 76 71 67 Average High Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 74 81 83 89 87 91 90 87 83 83 80 73 Average Low Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 52 53 61 62 69 68 70 68 69 68 62 61 Highest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 81 87 89 94 95 97 102 93 90 90 84 82 Lowest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 44 61 44 56 57 63 63 63 62 62 57 57 • HIGHLANDS REGION The Highlands region is cool and relatively dry (200-400mm rain annually) with less humidity than the previous two regions.. • In the upper highlands, night-time temperatures can drop to below freezing. On these cold nights Calyptratus has been seen to overnight in fissures in the ground and the centre of thick bushes. • Sana'a is a typical highland town. • Average Temperature (°F) • Jan. 62 Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 65 68 69 72 75 76 74 73 66 62 60 Average High Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 72 74 76 76 80 83 83 81 80 75 72 71 Average Low Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 51 55 60 61 65 67 68 67 65 56 51 50 Highest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 84 84 88 89 91 90 91 91 91 93 85 84 Lowest Recorded Temperature (°F) Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. 34 37 46 48 45 52 48 45 48 39 34 32 ADEN Aden, Yemen) weather station over the course of an average year. It is based on the historical records from 2006 to 2012. Climate data for Aden Month Average high °C (°F) Average low °C (°F) Rainfall mm (inches) Avg. rainy days Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year 28 29 30 32 35 37 37 36 36 33 30 30 32.8 (82) (84) (86) (90) (95) (99) (99) (97) (97) (91) (86) (86) (91) 21 22 23 24 26 28 28 27 27 23 22 21 24.3 (70) (72) (73) (75) (79) (82) (82) (81) (81) (73) (72) (70) (75.8) 3 4 6 5 1 1 4 4 7 1 2 2 40 (0.12) (0.16) (0.24) (0.2) (0.04) (0.04) (0.16) (0.16) (0.28) (0.04) (0.08) (0.08) (1.6) 1 1 1 0 0 0 1 1 0 0 0 0 5 8 8 9 9 10 9 7 8 9 10 9 9 8.8 Mean daily sunshi ne hours Aden mean sea temperature[1] Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 26 °C (79 °F) 26 °C (79 °F) 27 °C (81 °F) 28 °C (82 °F) 30 °C (86 °F) 31 °C (88 °F) 30 °C (86 °F) 29 °C (84 °F) 30 °C (86 °F) 29 °C (84 °F) 28 °C (82 °F) 27 °C (81 °F) HADHRAMOUT Hadhramout This report describes the typical weather at the Sayun Airport (Sayun, Yemen) weather station over the course of an average year. It is based on the historical records from 2008 to 2012. SOCOTRA IS THE MAIN ISLAND The climate of Socotra is classified in the Köppen climate classification as BWh and BSh, meaning a tropical desert climate and semi-desert climate with a mean annual temperature over 25 °C (78 °F). Yearly rainfall is light, but is fairly spread throughout the year. Climate data for Socotra Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Average high °C (°F) 27.2 28.5 30.5 (81) (83.3) (86.9) 32.7 34.2 33.9 32.0 32.3 32.7 31.4 29.8 28.0 31.1 (90.9) (93.6) (93) (89.6) (90.1) (90.9) (88.5) (85.6) (82.4) (87.98) Daily mean °C (°F) 22.0 23.4 25.1 27.5 28.9 29.0 27.6 27.5 27.6 26.0 24.2 22.7 25.96 (71.6) (74.1) (77.2) (81.5) (84) (84.2) (81.7) (81.5) (81.7) (78.8) (75.6) (72.9) (78.73) Average low °C (°F) 16.8 (62.2) 18.3 19.8 22.2 23.7 24.1 23.2 22.8 22.6 20.6 18.7 17.5 20.86 (64.9) (67.6) (72) (74.7) (75.4) (73.8) (73) (72.7) (69.1) (65.7) (63.5) (69.55) Precipitation mm (inches) 23 18 14 22 37 18 12 15 27 38 18 16 258 (0.91) (0.71) (0.55) (0.87) (1.46) (0.71) (0.47) (0.59) (1.06) (1.5) (0.71) (0.63) (10.16) 2.0 2.0 2.1 3.4 4.1 6.0 9.7 9.3 4.9 3.2 3.0 3.0 52.7 20 21 24 27 29 29 28 27 27 25 22 21 25.2 Avg. precipitat ion days (≥ 0.0 mm) % humidity THE NATURE OF YEMEN THE NATURE OF YEMEN The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • The nature of Yemen • Thank you so much • Teacher : Fathi Hawash •