In 2024, residents of the Mexican state of Jalisco faced unusual weather. Typically, rains begin in June, but that year they were delayed until late July and ended by mid-September. Meanwhile, some areas received too much rainfall, while others got too little. Temperatures, meanwhile, were the highest on record: on average 2.3°C above normal.

Why did this happen? A high-pressure system, an anticyclone with clear skies, lingered over Mexico for a long time. It acted like a lid on a pot: it prevented clouds from rising and releasing rain, while the ground beneath it kept heating up. It's like covering a skillet with a lid and leaving it on the stove: it gets hot inside, and steam can't escape.

Now farmers in Jalisco are having to adjust their planting schedules and prepare for increasingly unpredictable rains. The thermometer, which once simply showed the temperature, has become a warning that the climate is changing.