Lightning network is not yet here officially. It works on the test network, and the number of the LN nodes and connections on the mainnet are growing day by day but it's still a testing period, so this won't affect the transaction fees directly. Segwit is the thing that has an effect on the transaction fees, as if more and more wallets are using segwit, the transactions would get smaller then before, so one block would contain more transactions like before, so the price of getting into a block (tx fee) will become lower a bit. Also, as already mentioned here, Christmas was a really busy period of the year, so now there are less people who want to send a transaction, this also makes the tx fee lower.