Since 1939, Modesto temperatures have reached the century mark only six times in the first half of May. If the National Weather Service forecast is correct, Modesto could add at least two more days to that number this week.
Forecasters are predicting triple-digit weather Thursday and Friday, and the heat could extend into the weekend.
An unusual heat wave could prove to be harmful to crops, dangerous to forest land and deadly to people and pets if proper precautions aren't taken.
The only time Modesto endured consecutive triple-digit days in mid-May was May 6-7 in 1987, according to records from the Modesto Irrigation District.
The weather pattern affecting the Northern San Joaquin Valley and most of the West is typical for the summer and just a little early, said George Cline, a weather service forecaster.
Satellite images show a cloudless Earth from San Francisco to the Colorado border.
Cline expects Thursday to be the hottest for Modesto, with the high around 102, and the 100-degree weather could extend into Saturday and Sunday.
While the weather service is predicting that Modesto will hit the triple-digit mark Thursday, Weather Underground forecasters think it won't happen until Saturday with a high of 101.
Nevertheless, Weather Underground predicts the high to be around 99 on Thursday and Friday.
Cline said the gusty north wind should ebb by Friday, and the temperatures should dip back into the 80s by Monday.
High wind and heat have played a role in blazes that created havoc earlier this week. Forecasts of triple-digit weather only add more fuel to the fears of forest land managers.
"It's as dry now as it ever has been (at this time of the year)," said Jerry Snyder, a spokesman for the Stanislaus National Forest. "Factor in increased temperatures and wind, and you have all the elements for a serious wildfire."
Snyder wanted to remind campers they need a fire permit even for cooking stoves if they are used outside a park or developed recreation area.
One safety requirement is a 10-foot clearance area around all fires. He added, "If you don't need a fire, don't start one."
While forest watchers have their fingers crossed because of prime fire conditions, farm officials are merely cautious about the heat wave.
Ed Perry, a Stanislaus County farm adviser with the University of California Cooperative Extension, said only one local crop is being harvested -- cherries.
He said the heat may hasten the cherry harvest a bit, but the wind is likely to do more damage with some early fruits falling or being bruised as branches rub together.
Growers may need to start irrigating sooner because plants need more water in the heat, Perry said.
Keeping people and pets cool also is a concern.
Children and seniors are especially vulnerable to heat, health experts say. People should limit extreme outdoor activity and keep hydrated.
According to the Humane Society Web site, pets can suffer from heat exhaustion and heat stroke, resulting in death. Signs of heat stress include heavy panting, glazed eyes, a rapid pulse, unsteadiness, vomiting, or a deep red or purple tongue.
Owners need to lower the animal's body temperature by moving the pet into the shade and dousing it with cool water. Let the pet drink small amounts of water and get it to a veterinarian immediately.
Humane Society of Stanislaus County President Traci Jennings reminded residents to provide lots of clean, fresh water for pets and avoid leaving them in the car, even in the shade.