I wear a mask in all public spaces where I'm likely to encounter people, both indoors and outdoors, which functionally means I mask whenever I leave my room (I live in a dorm rn). To monitor the pandemic, I generally go with the Pandemic Mitigation Collaborative reports; it relies on wastewater data because that's the best we have now. I mask all the time irrespective of whether or not there is a spike, because even when there isn't a spike there's still a lot of COVID going around. That's just the world we live in now. The type of mask matters as well; an N95 will give a lot more protection than a surgical mask. That being said, any mask is better than no mask at all.