It is early in the 2016 calendar year, but I thought it would be interesting to take a look at how many USTA League matches were played in each month of the 2015 calendar year.
The below chart shows the number of team matches in the Women's and Men's 18 & over, 40 & over, and 55 & over leagues during last year.
The chart isn't terribly surprising as most areas have leagues in the Spring and March thru June are the busiest months for the main leagues. But there is still quite a bit of play in January and February, probably in leagues where there is indoor play or the South, and July in areas where leagues are finishing up.
If 2016 follows this trend, we are now nearing the meat of the league season. Have fun getting out on the courts and playing!