We have been doing indoor clinics for our 6 year old at the national cathedral school (super convenient on Wisconsin Ave), with KidsProSoccer, in the youth program, and with my 8 year old, we have training in Arlington as he is already in a team, also run by KPS. Both locations are very easy to get to, and the their training is really fantastic.

Several DC rec centers have indoor soccer classes over the winter. Call the ones closest to you. And some gyms have indoor futsal. I know Bethesda Sport & Health has good futsal clinics, but I'm sure there are others.

Have a fun/good winter soccer clinic to recommend? This would be for winter, in DC (or nearby MD/VA) and for 9/10 year old, boys or co-Ed.
Thank you for any recommendations.