I've noticed that radiation levels spike the most in west coast cities that have mountains on their east side.
Sacramento (east is Sierras) and all central valley cities on down Cal. have had significant radiation spikes (compared to coastal cities in Ca and WA)
Yuma AZ has been hit very hard. There is a mountain ridge immediately east of Yuma.
Phoenix too, with its mountains to the east.
Although, Phoenix has been less impacted than Yuma, since Yuma's mountains are west of it.
TRAPPED AIR MUST MEAN HIGHER RADIATION ON THE WEST COAST
Why did it take me so long to figure that out!