Amid favorable environmental conditions, the cyclone underwent rapid intensification on May 29, strengthening into a Category 2 hurricane and reaching peak winds of 110 mph (180 km/h).

On the afternoon of May 30, the hurricane made landfall just west of Puerto Ángel, Oaxaca, with slightly weaker winds of 105 mph (169 km/h).

[5] By 06:00 UTC on May 26, the disturbance's showers and thunderstorms began to show some signs of organization while located a few hundred miles south of the Gulf of Tehuantepec.

[8] The depression strengthened into Tropical Storm Agatha around 09:00 UTC that same day, while centered about 220 mi (350 km) south-southwest of Puerto Ángel, Oaxaca.

[14] At 21:00 UTC, Agatha was upgraded to a Category 2 system, as Hurricane Hunter aircraft found peak winds of 110 mph (180 km/h) and a minimum barometric pressure of 964 millibars (28.5 inHg), while retaining its intensity.

[15][16] Agatha's rapid intensification appeared to level off in the early hours of May 30, and the hurricane began an anticipated turn to the northeast.

[17] Later that day, as the core of the system approached the coast of Mexico, the satellite presentation of the storm displayed hints of an eye occasionally appearing within the central dense overcast, and convection remained quite deep and symmetric around the center.

[3] All of these fatalities were due to freshwater flooding in the Sierra Madre del Sur, with some people swept away by overflowing rivers or buried by mudslides.