Question: Where is the Delta variant most common in the United States?  Thinking about my summer travel plans….

Answer: Based on data from CDC’s national genomic surveillance program, Missouri is the state with the highest proportion of circulating Delta variant; 73% of all sequenced samples between mid-May and mid-June were Delta variant.   Nevada and Colorado are the states with the second and third highest Delta variant levels (40% and 36%, respectively).  Missouri is also the state with the highest number of weekly cases per population (16 cases per 100,000 population over the last 7 days), followed by Arkansas and Nevada.  As you’re traveling, and especially if you are traveling with younger children or other unvaccinated/at-risk folks, I suggest that you try to avoid hot spot and high risk counties (e.g. most of Missouri, Figure).  You can easily track such counties using the NY Times COVID maps. 

Figure. Risk levels by county (from NY Times)