In Cuernavaca, 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 Cuernavaca begins around October 31 and lasts for 6.8 months, ending around May 24. On February 25, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 70% of the time, and overcast or mostly cloudy 30% of the time.

The cloudier part of the year begins around May 24 and lasts for 5.2 months, ending around October 31. On September 12, the cloudiest day of the year, the sky is overcast or mostly cloudy 89% of the time, and clear, mostly clear, or partly cloudy 11% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Cuernavaca varies very significantly throughout the year.

The wetter season lasts 4.4 months, from May 28 to October 9, with a greater than 40% chance of a given day being a wet day. The chance of a wet day peaks at 79% on August 27.

The drier season lasts 7.6 months, from October 9 to May 28. The smallest chance of a wet day is 2% on December 8.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 79% on August 27.

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. Cuernavaca experiences extreme seasonal variation in monthly rainfall.

The rainy period of the year lasts for 6.4 months, from April 26 to November 9, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 1, with an average total accumulation of 6.0 inches.

The rainless period of the year lasts for 5.6 months, from November 9 to April 26. The least rain falls around December 11, with an average total accumulation of 0.1 inches.

The length of the day in Cuernavaca varies over the course of the year. In 2017, the shortest day is December 21, with 10 hours, 60 minutes of daylight; the longest day is June 21, with 13 hours, 16 minutes of daylight.

The earliest sunrise is at 6:30 AM on April 1, and the latest sunrise is 1 hour, 5 minutes later at 7:35 AM on October 28. The earliest sunset is at 5:57 PM on November 24, and the latest sunset is 2 hours, 21 minutes later at 8:18 PM on July 4.

Daylight saving time (DST) is observed in Cuernavaca during 2017, starting in the spring on April 2, lasting 6.8 months, and ending in the fall on October 29.

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 Cuernavaca, 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, remaining a virtually constant 0% 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 Cuernavaca does not vary significantly over the course of the year, remaining within 0.4 miles per hour of 2.6 miles per hour throughout.

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

The wind is most often from the south for 6.1 months, from January 5 to July 8, with a peak percentage of 49% on June 2. The wind is most often from the east for 2.7 months, from July 8 to September 30, with a peak percentage of 44% on July 22. The wind is most often from the north for 3.2 months, from September 30 to January 5, with a peak percentage of 30% on January 1.

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 brighter period of the year lasts for 2.5 months, from March 5 to May 20, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest day of the year is April 1, with an average of 7.2 kWh.

The darker period of the year lasts for 2.5 months, from November 8 to January 24, with an average daily incident shortwave energy per square meter below 5.4 kWh. The darkest day of the year is December 22, with an average of 5.0 kWh.

For the purposes of this report, the geographical coordinates of Cuernavaca are 18.926 deg latitude, -99.231 deg longitude, and 5,085 ft elevation.

The topography within 2 miles of Cuernavaca contains very significant variations in elevation, with a maximum elevation change of 942 feet and an average elevation above sea level of 5,070 feet. Within 10 miles contains very significant variations in elevation (7,631 feet). Within 50 miles also contains extreme variations in elevation (15,568 feet).

The area within 2 miles of Cuernavaca is covered by artificial surfaces (76%) and cropland (21%), within 10 miles by trees (42%) and cropland (35%), and within 50 miles by cropland (37%) and trees (37%).

This report illustrates the typical weather in Cuernavaca, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in central Cuernavaca.

Note: Since Cuernavaca is located on a hillside, those in the north of Cuernavaca will experience temperatures slightly lower than average and those in the south will experience temperatures slightly higher. For those vacationing in Cuernavaca, you can decide which part of the city to stay depending on your preference for warmer or cooler. You can expect 5 to 10˚F difference between the north and south of the downtown.

For each station, the records are corrected for the elevation difference between that station and the center of Cuernavaca according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Cuernavaca is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Cuernavaca and a given station.

The stations contributing to this reconstruction are: Licenciado Adolfo López Mateos International Airport – Cuernavaca (28%, 58 kilometers, northwest); Benito Juárez International Airport – Mexico City (43%, 59 kilometers, north); and Hermanos Serdán International Airport – Puebla (29%, 94 kilometers, east).

Other Data

All data relating to the Sun’s position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA’s MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA’s Jet Propulsion Laboratory.