Fox News Weather Center

Sunshine, Warmth to Prevail for 2015 Kentucky Derby

The sun will shine bright for the 2015 Kentucky Derby on Saturday at legendary Churchill Downs in Louisville.

For the crowd of more than 100,000 expected to watch the 20 horses in the field "Run for the Roses," seasonable temperatures and sunny skies will set the scene for an ideal race day. Post time for the 141st Derby is approximately 6:24 p.m. EDT Saturday.

While it will be a beautiful day to be outdoors, racegoers will certainly want to apply plenty of sunscreen as a UV index of 8 is predicted for Saturday. A reading of 8-10 brings a "very high risk of harm from unprotected sun exposure," according to the Environmental Protection Agency.

In the days leading up to the race, an upper-level disturbance will bring cool and unsettled weather to the region Thursday with times of clouds and sun, according to Senior Meteorologist Carl Erickson.

"While much of the time will be rain-free, there will be a couple of showers around," Erickson said. "With the clouds and precipitation in the area, temperatures will be several degrees below average in the middle 60s."

However, as race day approaches, high pressure will build in for Friday and Saturday, bringing more sunshine and higher temperatures.

"Both days are shaping up to be nice, with highs on Friday in the lower 70s and into the middle 70s Saturday," Erickson said. A common high temperature for this time of year in Louisville is around 74 F.

The 141st Kentucky Oaks, a race for 3-year-old fillies, will be run at 5:45 p.m. on Friday.

Milder conditions are preferable for the Derby, because if it's a hot, humid day, a horse could expend more energy just walking out to the starting gate, said Charles Lyman, owner of Maui Meadow Farm, a thoroughbred farm in West Chester, Pennsylvania.

In those situations, and depending on the horse's temperament, "[The horse] is already running his race before he gets out to the starting gate," said Lyman.

"You don't want it to be 90 and humid, everybody's going to be all hot and flustered," he said. "But it's Kentucky in the spring, most of the time it's mild and nice."

Dry weather will also eliminate the risk of horses running on a muddy track, which can be a key factor in deciding the race.

"On a muddy track, some horses just absolutely hate it and other horses, they just love it," Lyman said.

Lyman, who oversees about 70 horses of varying ages at his farm, said most of the top trainers take their horses south, avoiding the cold in the winter. Then, when it's time to race in the Derby, the horses are already well acclimated to the weather.

"It's not like you [have] horses coming from Canada... coming out of 30 degrees and all of a sudden it's 70 degrees," Lyman said. "It's not a shock for them."