How to Read the UV Index
How SunUp Displays UV Throughout the Day
UV is not constant throughout the day — it follows a curve that peaks between 10am and 2pm solar time and drops dramatically in the morning and evening. SunUp shows this as a hourly chart on the dashboard, letting you see when UV will be highest and lowest. The chart updates in real-time as weather conditions change. You can scroll forward in the chart to see tomorrow and the next 48 hours.
Try it in the app:
Scroll the hourly chart on SunUp's dashboard left and right. Notice how UV rises through the morning, peaks, and falls in the afternoon.
Pro tip:
Early morning (before 9am) and late afternoon (after 4pm) UV levels are typically 50-70% lower than midday peaks. Scheduling outdoor activities during these windows is the easiest UV reduction strategy.