Okay, you need to know a few things:
(1) Israel is in the Mediterranean climate zone--quite mild all the time. The US is made up of a bunch of climates--but about 5/6ths of the US is going to be very cold from now through the end of February/beginning of March. The only areas that won't be freezing are in the areas from San Diego, California across to the southern tip of Florida. Even some of these areas will get a bit cool/cold.
From here in San Jose, California (I live nearby), head down the coast through Monterey and Carmel, then down to San Simeon and visit Hearst Castle, then south through Pismo Beach, through Solvang, down to Santa Barbara, and through Los Angeles and down to San Diego.
From San Diego go east through Yuma and up to Phoenix, then east through Tucson, onto Carlsbad Caverns in New Mexico, and on to El Paso, Texas. In Texas, head east to San Antonio, take a detour up to Austin, then head on over through Houston and on to New Orleans. From New Orleans go north to Memphis, then head east to Nashville, then come back south to Atlanta, and south down to Jacksonville, then on to Orlando (and Disney World), then down to Miami, then down to the Florida Keys and all the way to Key West (the southernmost point in the US). At ths point, you'll finally be warm (and happy), and enjoying rum drinks or margaritas and living the good life.
Write back after you get this far--and we'll give you the next part of the trip to take.
P.S. This trip will take you anywhere from four weeks to 8 weeks depending upon how fast you go (I'm presuming you'll take at least a few days at each key place). You can also go north from Phoenix to Albuquerque and Santa Fe and then down to Carlsbad Cavern if you want, but then you will hit snow in the Santa Fe area.
Enjoy.