Record-breaking Guanajuato May rainfall flooded streets in León, Guanajuato city and San Miguel de Allende yet helped reservoirs recover and may ease lingering drought.
After a dry spring, central Guanajuato saw an unprecedented surge of rainfall in May. At the end of the month, the statewide average accumulated rainfall reached 48.4 mm—nearly double the 26.4 mm recorded in May 2024. That sharp rise translated into localized downpours that overwhelmed drainage systems, leaving several underpasses, tunnels and city streets submerged.
Officials in León reported 84 mm of rain during May—a fourfold increase over the 22 mm seen last year—while Guanajuato city tallied 42.4 mm as of midday Saturday, eclipsing the previous record of 41 mm set in May 1991 and again in May 2020. Even San Miguel de Allende, better known for its colonial charm than its flood risk, faced sudden downpours that left drivers stranded in knee-deep water.
Meteorologists say this surge was unusually early and intense. “It has been far rainier here in May than normal,” stated Marcos Esquivel, director of the Atmospheric Sciences Department at the University of Guanajuato. While higher precipitation usually offers relief from drought, the sheer volume caught many city dwellers off guard. In Guanajuato city and León, streets turned into swift currents, and shopkeepers spent each morning sweeping mud and debris from storefronts. Multiple vehicles stalled in deep water as drivers attempted to navigate flooded tunnels.
In Guanajuato city, residents also watched nervously as the Presa de la Olla reservoir on the outskirts began spilling over its spillways—an event typically reserved for late June. The sight surprised long-time residents who recall that under normal conditions, the reservoir only reaches those levels closer to mid-rainy season. Elsewhere in the state, drought-stricken reservoirs gained precious volume. The Ignacio Allende reservoir near San Miguel de Allende rose to 46 percent capacity, while the Solis reservoir near Acámbaro surpassed 60 percent, pushing the cumulative capacity of the region’s reservoirs above 50 percent as of Thursday.
Still, recovery has been uneven. In northern Guanajuato, the El Palote reservoir near León inched up from 3.5 percent to just 6 percent capacity, and the Peñuelitas reservoir near Dolores Hidalgo sat at 5.5 percent as of Sunday, highlighting persistent water shortages in those districts.
Experts note that the early onset of heavy rains carries both benefits and risks. Esquivel explained that although urban flooding created immediate disruptions, the precipitation will help recharge depleted aquifers and ultimately benefit the agriculture sector in the Bajío, one of Mexico’s most productive farming regions. More than two-thirds of Mexico’s breadbasket outputs come from states in and around this region, so even a short-term boost in water tables can ease strain on crops as planting continues.
The Bajío sits at the heart of Guanajuato state, spanning fertile plains that supply corn, beans and vegetables across central Mexico. Farmers had braced for another season of below-average rainfall after months of drought. Now, with reservoirs climbing to mid-level capacity in many areas, irrigation canals can run closer to full tilt. That should translate into steadier water availability through June and July, critical months for summer crops.
State authorities also shared a regional outlook: showers are set to continue across central Mexico this week. Forecasts project rain from the Valley of Mexico through El Bajío, extending as far west as Colima. Meanwhile, storms will push into Oaxaca, Veracruz, Chiapas, Tabasco, Campeche and the Yucatán Peninsula. At the same time, severe heat—temperatures topping 40 to 45 °C—is expected in Sonora, Chihuahua, Coahuila, Tamaulipas, San Luis Potosí, Durango, Sinaloa, Michoacán and Guerrero.
Those forecasts suggest a volatile mix. In Guanajuato city and León, the strategy has shifted to rapid cleanup and reinforcing vulnerable points in drainage systems. Crews have been dispatched nightly to clear storm drains, and municipal officials have urged drivers to avoid flooded roads. School closures and schedule adjustments were announced in certain districts to keep students safe where water has lingered in low-lying areas.
In San Miguel de Allende, local officials said they were monitoring the Ignacio Allende reservoir closely, aware that uncontrolled releases could exacerbate downstream flooding. Contractors have been stationed along spillways to manage overflow and ensure water moves into designated channels rather than major streets.
Looking ahead, the early rains can help avert a repeat of last summer’s drought crisis. According to state water managers, April and May are typically the driest months. A dry April and early May depleted rivers and wells, leaving reservoirs at historic lows. By contrast, May 2025’s figures show that Guanajuato has recovered almost half of its pre-drought water volume in just three weeks. That should allow irrigation districts serving sugarcane and vegetable farms to switch from emergency restrictions to normal water rotations.
Community groups have mixed reactions. In León, home gardeners say they welcome any rain, even if it means muddy yards and soaked fences. “We needed this,” a local cucumber farmer said. “If these rains keep up, we’ll see better yields come July”. But residents living near creek beds remain on alert. Emergency personnel have already rescued a handful of drivers who misjudged water depth in underpasses.
As the rainy season gains momentum, officials warn that more rain could mean more flooding. Anyone traveling through tunnels or crossing low bridges must exercise caution. Still, the broader message is that May 2025’s downpours likely mark a turning point after months of parched fields and dwindling reservoirs. For now, the challenge is to manage excess water while planning for a summer harvest that hinges on steady irrigation.
With local reservoirs already rebounding—Ignacio Allende at 46 percent and Solis at 60 percent—and continued rainfall on the horizon, Guanajuato’s farmers and city officials hope to strike a balance between flood control and drought relief. One thing is clear: after a spring that many feared could bring a repeat of last year’s water shortages, this Guanajuato May rainfall appears to be rewriting the region’s 2025 water story—one reservoir at a time.
