You can temporarily pause monitoring in two different ways.
If you need to pause monitoring for a specific host, or group of hosts, you can pause individual hosts via the Manage -> Hosts section of the portal. Simply check all the hosts you’d like to pause, and the click the Pause link at the top of the list.
If you need to temporarily pause all monitoring across your entire account, you can turn off the Enable Monitoring option, from the Account -> Settings section:
All monitoring, for all hosts under your your account will be paused until this option is re-enabled.