Milpa Alta is a borough (demarcación territorial) in Mexico City. It lies in the southeast corner of the nation's capital, bordering the State of Mexico and Morelos. It is the least populated, second largest and most rural of all the boroughs. It is also one of the most traditional areas of the city, with over 700 religious and secular festivals during the year and an economy based on agriculture and food processing, especially the production of nopal cactus, barbacoa and mole sauce.
Geography and environment
The borough of Milpa Alta is located in the southeast of Mexico City bordering the boroughs of Xochimilco, Tláhuac and Tlalpan, with the state of Morelos to the south and the State of Mexico to the west. It has the second largest territorial extension after Tlalpan, occupying 268.6km2.
The terrain is rugged mostly consisting of volcanic peak along with some small flat areas mostly formed in the Cenozoic Era. City officials have classified the entire borough as a conservation zone, important for its role as an aquifer recharge area as well as its forests. Forest, farmland and grazing areas constitute 98.1% of the total surface area.
It has an average altitude of 2,420 meters above sea level with altitudes varying between 2,300 and 3,600. It is part of the Trans-Mexican Volcanic Belt and the Sierra Chichinautzin volcanic mountain chain, which separates Mexico City from the state of Morelos. The borough is divided into three zones: Ajusco-Teuhtli, the lowest elevations, Topilejo-Milpa Alta in the medium range and Cerro-Tlicuaya at the highest elevations. The main elevations are volcanic and include Cuautzin (3,510), Tulmiac, Ocusacayo (3,220), La Comalera (3,230), San Bartolo (3,200), Tláloc (3,510), Chichinautzin (3,470), Yecahuazac, Quimixtepec, El Oclayuca (3,140), El Pajonal (3,100), El Ocotécatl (3,480), Acopiaxco (3,320), Tetzacoatl (3,310), Tehutli (2,800) Cilcuayo (3,580), Nepanapa (3,460), Texalo (3,560), Oclayuca (3,390), San Miguel (2,988) .
The area belongs to the Amacuzac River basin but only small streams run on the surface. It has ample surface water but confined to small springs and streams which over time have formed a succession of narrow valleys or micro-basins, which are important for recharging the Valley of Mexico’s aquifers. These micro-basins include Cilcuayo, Río Milpa Alta and Cocpiaxco and contain the borough’s main towns.
Most of the area has a temperate climate, with cold climates found at the highest elevations. The average annual temperature is with average lows at and averages highs at . Average annual precipitation is . Freezing temperatures occur occasionally from October to March especially in the higher elevations. The windiest months are February and March. On the Koppen scale, its climate is described as C (W2) (w) b (i’) which signified a relatively moist climate, with a rainy season in the summer especially in July and August. However, the climate varies substantially in the territory based mostly on altitude, with six sub-climates: C(E)(w2) which is relatively cold, C(E)(m) also relatively cold but wetter, C(w1) a temperate climate, C (w2) a températe and relatively wet climate, C ( w1) temperate and relatively dry and C ( w2) which is relatively cold with rains falling mostly in the highest areas.