I think pistachio needs cold spells to fruit properly.
"Pistachios require long, hot, dry summers and chilling in the winter, but don't tolerate ground that freezes. They require approximately 1,000 accumulative hours of temperature at or below 45° F during dormancy.
...
Pistachios have the narrowest environment requirements of any commercially grown nut crop. ...In the United States, that pretty much limits growth to the San Joaquin Valley in California, southeastern Arizona, far west Texas and the high desert of New Mexico."
"Pistachios require long, hot, dry summers and chilling in the winter, but don't tolerate ground that freezes. They require approximately 1,000 accumulative hours of temperature at or below 45° F during dormancy. ... Pistachios have the narrowest environment requirements of any commercially grown nut crop. ...In the United States, that pretty much limits growth to the San Joaquin Valley in California, southeastern Arizona, far west Texas and the high desert of New Mexico."
https://wikifarmer.com/pistachio-tree-growing-conditions/