After the dry heat of early spring, the arrival of seasonal rains in central Mexico in May is often a welcome relief. However, showers have turned into record-setting downpours in some areas, flooding streets, tunnels and underpasses in some cities. 

In the state of Guanajuato, residents of León, Guanajuato city and San Miguel de Allende have been caught off guard by incessant rainfall. At the end of May, the average accumulated rainfall for the entire state was 48.4 mm (48 liters per square meter); in 2024, it was only 26.4 mm.

Officials in León reported that 84 mm of rain fell in May, nearly quadrupling the amount of rain recorded last year (22 mm). In Guanajuato city, a record 42.4 mm of rain had fallen as of midday Saturday, surpassing the record 41 mm seen in May 1991 and May 2020.

“It has been far rainier here in May than normal,” said Marcos Esquivel, the director of the Atmospheric Sciences Department at the University of Guanajuato. 

Though Esquivel said the precipitation is favorable in hydric and environmental terms, the excess water has flooded streets and tunnels in Guanajuato city and León, causing several cars to stall out in deep water. Shopkeepers in Guanajuato city were sweeping mud and accumulated garbage from their storefronts each morning over the weekend.

Residents in the state capital reported that the Presa de la Olla reservoir on the outskirts of Guanajuato city was overflowing into the spillways, an eventuality that doesn’t typically occur until late June.

In other parts of the state, reservoirs that are well below capacity due to years of drought are recovering nicely. The Ignacio Allende Reservoir near San Miguel de Allende had risen to 46% capacity and the Solis Reservoir near Acámbaro had surpassed 60% capacity, boosting the cumulative capacity of reservoirs across the state to above 50% as of Thursday.

Still, the northern regions of the state have not been so lucky. The El Palote Reservoir near León had risen from a low of 3.5% capacity to only 6% capacity and the Peñuelitas Reservoir near Dolores Hidalgo was at 5.5% as of Sunday.

Esquivel said the early onset of heavy rains will not only continue to mitigate the effects of drought, but will also have a positive impact in the agriculture sector and will recharge aquifers in the region.

The state of Guanajuato sits in the heart of the geographical region known as the Bajío, which is one of the most productive agricultural regions in Mexico.

Rain forecast for this week

Showers will continue this week in the Valley of Mexico and the Bajío states, with rain forecast as far west as Colima.

Storms are in the forecast for Oaxaca, Veracruz, Chiapas, Tabasco, Campeche and the Yucatán Peninsula, and severe heat (40 to 45 degrees Celsius) is expected in Sonora, Chihuahua, Coahuila, Tamaulipas, San Luis Potosí, Durango, Sinaloa, Michoacán and Guerrero.

With reports from Periódico AM, La Silla Rota and El Sol de León