The climate in Mexico

Climate zone: The northern parts of Mexico are in the subtropics, the southern regions in the tropics.
It is warm to hot all year round and invites to bathe at average water temperatures of 26 degrees. The warmest and at the same time rainiest region is Yucatan Peninsula. The coldest is Central-South.

Temperature records of the last 73 years

The hottest temperature measured from 1949 to July 2022 was reported by the Ejido Nuevo Leon weather station. In July 2017 the record temperature of 49.8 °C was reported here. The hottest summer from July to September, based on all 80 weather stations in Mexico below 2720 metres altitude, was recorded in 1993 with an average temperature of 25.7 °C. This average temperature will normally be measured every 4 to 6 hours, thus also including the nights. Normally, this value is 24.9 degrees Celsius.
The coldest day in these 73 years was reported by the weather station Temosachic. Here the temperature dropped to -21.0 °C in February 2011. Temosachic lies at an altitude of 1932 meters above sea level. The coldest winter (January to March) was in 2010 with an average temperature of 17.6 °C. In Mexico, it is usual to have about 1.6 degrees more at 19.2 °C for this three-month period.
The most precipitation fell in September 1952. With 46.7 mm per day, the Manzanillo weather station recorded the highest monthly average of the last 73 years. Incidentally, the region with the most rainfall for the whole year is around Coatzacoalcos. The driest region is near La Paz.

Long-term development of temperatures from 1998 - 2021

In contrast to single record values, a long-term development cannot simply be brought about by all weather stations in the country. Both the number and the locations are constantly changing. A simply calculated average value would give a falsified result. If several measuring stations in particularly cold mountain or coastal regions are added in one year, the average would already decrease as a result of this alone. If a station fails during the summer or winter months, it does not provide any values and falsifies the average again. The subsequent long-term development was therefore reduced to only 3 measuring points in order to have actually comparable data over as long a period as possible.
In the years 1998 to 2021 there were only these 3 weather stations in the whole country, which reported continuous temperature values (La Paz, Manzanillo, Comitan). From these weather reports we have created a long-term development that shows the monthly average temperatures. The hottest month in this entire period was August 2019 with 27.2 °C. December 1999 was the coldest month with an average temperature of 19.0 °C.
The average annual temperature was about 23.1 °C in the years after 1998 and about 24.0 °C in the last years before 2021. So in less than 24 years it has increased by about 0.9 °C. This trend only applies to the selected 3 weather stations in Mexico. A considerably more comprehensive evaluation of the global warming has been provided separately.

Data basis and methodology

The data of the individual measuring stations are based on the archives of the German Weather Service, individual values averaged and supplemented by own elements. In order to determine a representative national average, average values were first calculated for each part of the country, which were then summarized at the national level. Thus, if a disproportionate number of weather stations are located in a small area, their number does not affect the national average. There are 81 stations in Mexico itself. In 12 cases, neighboring but nearby weather stations were also used to obtain more accurate values.