Climate Ready: Hottest July on record takes a toll on California's table grape harvest

FRESNO, Calif. -- It wasn't just your imagination; this past July was hotter than normal.

ABC30 meteorologist Christine Gregory, explains "The National Weather Service took an average of afternoon highs and the lows. You get what's called the mean temperature for the month of July, and it was actually the hottest July on record."

Fresno sweltered through 26 days of 100 degrees or more in July. The hottest day was 114.

"We haven't seen temperatures quite that hot in the past 20 or 30 years," said Gregory.

The San Joaquin Valley grows most of the nation's fresh-market table grapes.

That heatwave slowed the supply after sending shock waves through the growing community.

"All of a sudden, we looked, and we noticed sunburn on the grapes. Then, all of a sudden, the size was off a little bit. We applied more water, but it didn't really seem to do much," said grape grower George Matoian.

Matoian and his brother have been growing grapes in Fresno County near Easton for decades.

In addition to the sunburn, the prolonged triple-digit heat stunned the crop.

"This year, we're having a problem with the color grapes because it's just too hot. The vine just shut down and didn't want to color, didn't want to size the fruit and didn't want to sugar the fruit too," said Matoian.

For most of July, field workers needed to shorten their shifts to avoid heat-related illness.

"We had a lot of abbreviated days. We would start the morning around 5:30 am and pretty close to 10:30 am, we would get to 101 or 102, and we would shut the crew down, and that was it," said Matoian.

Since most table grapes are also packed in the field, the heat cut packing short too.

Another risk to workers is that the heat contributes to ground-level ozone.

"It's essentially a mix between sunlight and heat, and it sort of creates this chemical reaction between the pollutants in the air, car exhaust, wildfire smoke. All those things go hand in hand, and it creates this harmful chemical that goes into the air, the ozone," said Gregory.

For Matoian, aside from being delayed a few weeks, his grapes will be okay.

He hopes the heat didn't damage the vines long-term and that next summer will be more forgiving.

"Definitely get cozy with the idea that we are certainly capable of seeing this excessive heat. We are capable of doing it again. I'm not saying we're expecting every summer to follow this lead, but I think the trends show that we're certainly capable of seeing more summers like this in the future," said Gregory.