Looks like you've got MalwareBytes, McAfee, SQL Server, which by themselves can be IOPS heavy. First, pull out all the anti-malware stuff. If you have multiple anti-malware programs, they will compete for resources and chew up your disk queue. Have one and only one anti-malware program. If it's always the same time of day, then it's probably a scheduled activity. SQL Agents can have scheduled things, so can anti-malware, and backup programs. If you've got file sharing to clients, it could be scheduled activity on an endpoint. Also, clients could be running things like a daily SQL report. Further, make sure you have enough compute and RAM for an SQL server. Assuming this is the back-end for some business system, you're going to need a minimum of 4-cores and 8GB RAM. A cheap RAID controller, or software RAID can slow you down too. If you have old hard-drives, pushing 3 to 5 years, that can slow you down as well.
Hope that give you some direction.